土木工程外文翻译70683
土木工程毕业设计外文翻译原文+翻译
The bridge crack produced the reason to simply analyseIn recent years, the traffic capital construction of our province gets swift and violent development, all parts have built a large number of concrete bridges. In the course of building and using in the bridge, relevant to influence project quality lead of common occurrence report that bridge collapse even because the crack appears The concrete can be said to " often have illness coming on " while fracturing and " frequently-occurring disease ", often perplex bridge engineers and technicians. In fact , if take certain design and construction measure, a lot of cracks can be overcome and controlled. For strengthen understanding of concrete bridge crack further, is it prevent project from endanger larger crack to try one's best, this text make an more overall analysis , summary to concrete kind and reason of production , bridge of crack as much as possible, in order to design , construct and find out the feasible method which control the crack , get the result of taking precautions against Yu WeiRan.Concrete bridge crack kind, origin cause of formation In fact, the origin cause of formation of the concrete structure crack is complicated and various, even many kinds of factors influence each other , but every crack has its one or several kinds of main reasons produced . The kind of the concrete bridge crack, on its reason to produce, can roughly divide several kinds as follows :(1) load the crack caused Concrete in routine quiet .Is it load to move and crack that produce claim to load the crack under the times of stress bridge, summing up has direct stress cracks , two kinds stress crack onces mainly. Direct stress crack refer to outside load direct crack that stress produce that cause. The reason why the crack produces is as follows, 1, Design the stage of calculating , does not calculate or leaks and calculates partly while calculating in structure; Calculate the model is unreasonable; The structure is supposed and accorded with by strength actually by strength ; Load and calculate or leak and calculate few; Internal force and matching the mistake in computation of muscle; Safety coefficient of structure is not enough. Do not consider the possibility that construct at the time of the structural design; It is insufficientto design the section; It is simply little and assigning the mistake for reinforcing bar to set up; Structure rigidity is insufficient; Construct and deal with improperly; The design drawing can not be explained clearly etc.. 2, Construction stage, does not pile up and construct the machines , material limiting ; Is it prefabricate structure structure receive strength characteristic , stand up , is it hang , transport , install to get up at will to understand; Construct not according to the design drawing, alter the construction order of the structure without authorization , change the structure and receive the strength mode; Do not do the tired intensity checking computations under machine vibration and wait to the structure . 3, Using stage, the heavy-duty vehicle which goes beyond the design load passes the bridge; Receive the contact , striking of the vehicle , shipping; Strong wind , heavy snow , earthquake happen , explode etc.. Stress crack once means the stress of secondary caused by loading outside produces the crack. The reason why the crack produces is as follows, 1, In design outside load function , because actual working state and routine , structure of thing calculate have discrepancy or is it consider to calculate, thus cause stress once to cause the structure to fracture in some position. Two is it join bridge arch foot is it is it assign " X " shape reinforcing bar , cut down this place way , section of size design and cut with scissors at the same time to adopt often to design to cut with scissors, theory calculate place this can store curved square in , but reality should is it can resist curved still to cut with scissors, so that present the crack and cause the reinforcing bar corrosion. 2, Bridge structure is it dig trough , turn on hole , set up ox leg ,etc. to need often, difficult to use a accurate one diagrammatic to is it is it calculate to imitate to go on in calculating in routine, set up and receive the strength reinforcing bar in general foundation experience. Studies have shown , after being dug the hole by the strength component , it will produce the diffraction phenomenon that strength flows, intensive near the hole in a utensil, produced the enormous stress to concentrate. In long to step prestressing force of the continuous roof beam , often block the steel bunch according to the needs of section internal force in stepping, set up the anchor head, but can often see the crack in the anchor firm section adjacent place. So if deal with improper, in corner or component form sudden change office , block place to be easy to appear crack strengthreinforcing bar of structure the. In the actual project, stress crack once produced the most common reason which loads the crack. Stress crack once belong to one more piece of nature of drawing , splitting off , shearing. Stress crack once is loaded and caused, only seldom calculate according to the routine too, but with modern to calculate constant perfection of means, times of stress crack to can accomplish reasonable checking computations too. For example to such stresses 2 times of producing as prestressing force , creeping ,etc., department's finite element procedure calculates levels pole correctly now, but more difficult 40 years ago. In the design, should pay attention to avoiding structure sudden change (or section sudden change), when it is unable to avoid , should do part deal with , corner for instance, make round horn , sudden change office make into the gradation zone transition, is it is it mix muscle to construct to strengthen at the same time, corner mix again oblique to reinforcing bar , as to large hole in a utensil can set up protecting in the perimeter at the terms of having angle steel. Load the crack characteristic in accordance with loading differently and presenting different characteristics differently. The crack appear person who draw more, the cutting area or the serious position of vibration. Must point out , is it get up cover or have along keep into short crack of direction to appear person who press, often the structure reaches the sign of bearing the weight of strength limit, it is an omen that the structure is destroyed, its reason is often that sectional size is partial and small. Receive the strength way differently according to the structure, the crack characteristic produced is as follows: 1, The centre is drawn. The crack runs through the component cross section , the interval is equal on the whole , and is perpendicular to receiving the strength direction. While adopting the whorl reinforcing bar , lie in the second-class crack near the reinforcing bar between the cracks. 2, The centre is pressed. It is parallel on the short and dense parallel crack which receive the strength direction to appear along the component. 3, Receive curved. Most near the large section from border is it appear and draw into direction vertical crack to begin person who draw curved square, and develop toward neutralization axle gradually. While adopting the whorl reinforcing bar , can see shorter second-class crack among the cracks. When the structure matches muscles less, there are few but wide cracks, fragility destruction may take place in thestructure 4, Pressed big and partial. Heavy to press and mix person who draw muscle a less one light to pigeonhole into the component while being partial while being partial, similar to receiving the curved component. 5, Pressed small and partial. Small to press and mix person who draw muscle a more one heavy to pigeonhole into the component while being partial while being partial, similar to the centre and pressed the component. 6, Cut. Press obliquly when the hoop muscle is too dense and destroy, the oblique crack which is greater than 45?? direction appears along the belly of roof beam end; Is it is it is it destroy to press to cut to happen when the hoop muscle is proper, underpart is it invite 45?? direction parallel oblique crack each other to appear along roof beam end. 7, Sprained. Component one side belly appear many direction oblique crack, 45?? of treaty, first, and to launch with spiral direction being adjoint. 8, Washed and cut. 4 side is it invite 45?? direction inclined plane draw and split to take place along column cap board, form the tangent plane of washing. 9, Some and is pressed. Some to appear person who press direction roughly parallel large short cracks with pressure.(2) crack caused in temperature changeThe concrete has nature of expanding with heat and contract with cold, look on as the external environment condition or the structure temperature changes, concrete take place out of shape, if out of shape to restrain from, produce the stress in the structure, produce the temperature crack promptly when exceeding concrete tensile strength in stress. In some being heavy to step foot-path among the bridge , temperature stress can is it go beyond living year stress even to reach. The temperature crack distinguishes the main characteristic of other cracks will be varied with temperature and expanded or closed up. The main factor is as follows, to cause temperature and change 1, Annual difference in temperature. Temperature is changing constantly in four seasons in one year, but change relatively slowly, the impact on structure of the bridge is mainly the vertical displacement which causes the bridge, can prop up seat move or set up flexible mound ,etc. not to construct measure coordinate , through bridge floor expansion joint generally, can cause temperature crack only when the displacement of the structure is limited, for example arched bridge , just bridge etc. The annual difference in temperature of our country generally changes therange with the conduct of the average temperature in the moon of January and July. Considering the creep characteristic of the concrete, the elastic mould amount of concrete should be considered rolling over and reducing when the internal force of the annual difference in temperature is calculated. 2, Rizhao. After being tanned by the sun by the sun to the side of bridge panel , the girder or the pier, temperature is obviously higher than other position, the temperature gradient is presented and distributed by the line shape . Because of restrain oneself function, cause part draw stress to be relatively heavy, the crack appears. Rizhao and following to is it cause structure common reason most , temperature of crack to lower the temperature suddenly 3, Lower the temperature suddenly. Fall heavy rain , cold air attack , sunset ,etc. can cause structure surface temperature suddenly dropped suddenly, but because inside temperature change relatively slow producing temperature gradient. Rizhao and lower the temperature internal force can adopt design specification or consult real bridge materials go on when calculating suddenly, concrete elastic mould amount does not consider converting into and reducing 4, Heat of hydration. Appear in the course of constructing, the large volume concrete (thickness exceeds 2. 0), after building because cement water send out heat, cause inside very much high temperature, the internal and external difference in temperature is too large, cause the surface to appear in the crack. Should according to actual conditions in constructing, is it choose heat of hydration low cement variety to try one's best, limit cement unit's consumption, reduce the aggregate and enter the temperature of the mould , reduce the internal and external difference in temperature, and lower the temperature slowly , can adopt the circulation cooling system to carry on the inside to dispel the heat in case of necessity, or adopt the thin layer and build it in succession in order to accelerate dispelling the heat. 5, The construction measure is improper at the time of steam maintenance or the winter construction , the concrete is sudden and cold and sudden and hot, internal and external temperature is uneven , apt to appear in the crack. 6, Prefabricate T roof beam horizontal baffle when the installation , prop up seat bury stencil plate with transfer flat stencil plate when welding in advance, if weld measure to be improper, iron pieces of nearby concrete easy to is it fracture to burn. Adopt electric heat piece draw law piece draw prestressing force at the component ,prestressing force steel temperature can rise to 350 degrees Centigrade , the concrete component is apt to fracture. Experimental study indicates , are caused the intensity of concrete that the high temperature burns to obviously reduce with rising of temperature by such reasons as the fire ,etc., glueing forming the decline thereupon of strength of reinforcing bar and concrete, tensile strength drop by 50% after concrete temperature reaches 300 degrees Centigrade, compression strength drops by 60%, glueing the strength of forming to drop by 80% of only round reinforcing bar and concrete; Because heat, concrete body dissociate ink evaporate and can produce and shrink sharply in a large amount(3) shrink the crack causedIn the actual project, it is the most common because concrete shrinks the crack caused. Shrink kind in concrete, plasticity shrink is it it shrinks (is it contract to do ) to be the main reason that the volume of concrete out of shape happens to shrink, shrink spontaneously in addition and the char shrink. Plasticity shrink. About 4 hours after it is built that in the course of constructing , concrete happens, the cement water response is fierce at this moment, the strand takes shape gradually, secrete water and moisture to evaporate sharply, the concrete desiccates and shrinks, it is at the same time conduct oneself with dignity not sinking because aggregate,so when harden concrete yet,it call plasticity shrink. The plasticity shrink producing amount grade is very big, can be up to about 1%. If stopped by the reinforcing bar while the aggregate sinks, form the crack along the reinforcing bar direction. If web , roof beam of T and roof beam of case and carry baseplate hand over office in component vertical to become sectional place, because sink too really to superficial obeying the web direction crack will happen evenly before hardenning. For reducing concrete plasticity shrink,it should control by water dust when being construct than,last long-time mixing, unloading should not too quick, is it is it take closely knit to smash to shake, vertical to become sectional place should divide layer build. Shrink and shrink (do and contract). After the concrete is formed hard , as the top layer moisture is evaporated progressively , the humidity is reduced progressively , the volume of concrete is reduced, is called and shrunk to shrink (do and contract). Because concrete top layermoisture loss soon, it is slow for inside to lose, produce surface shrink heavy , inside shrink a light one even to shrink, it is out of shape to restrain from by the inside concrete for surface to shrink, cause the surface concrete to bear pulling force, when the surface concrete bears pulling force to exceed its tensile strength, produce and shrink the crack. The concrete hardens after-contraction to just shrink and shrink mainly .Such as mix muscle rate heavy component (exceed 3% ), between reinforcing bar and more obvious restraints relatively that concrete shrink, the concrete surface is apt to appear in the full of cracks crackle. Shrink spontaneously. Spontaneous to it shrinks to be concrete in the course of hardenning , cement and water take place ink react, the shrink with have nothing to do by external humidity, and can positive (whether shrink, such as ordinary portland cement concrete), can negative too (whether expand, such as concrete, concrete of slag cement and cement of fly ash). The char shrinks. Between carbon dioxide and hyrate of cement of atmosphere take place out of shape shrink that chemical reaction cause. The char shrinks and could happen only about 50% of humidity, and accelerate with increase of the density of the carbon dioxide. The char shrinks and seldom calculates . The characteristic that the concrete shrinks the crack is that the majority belongs to the surface crack, the crack is relatively detailed in width , and criss-cross, become the full of cracks form , the form does not have any law . Studies have shown , influence concrete shrink main factor of crack as follows, 1, Variety of cement , grade and consumption. Slag cement , quick-hardening cement , low-heat cement concrete contractivity are relatively high, ordinary cement , volcanic ash cement , alumina cement concrete contractivity are relatively low. Cement grade low in addition, unit volume consumption heavy rubing detailed degree heavy, then the concrete shrinks the more greatly, and shrink time is the longer. For example, in order to improve the intensity of the concrete , often adopt and increase the cement consumption method by force while constructing, the result shrinks the stress to obviously strengthen . 2, Variety of aggregate. Such absorbing water rates as the quartz , limestone , cloud rock , granite , feldspar ,etc. are smaller, contractivity is relatively low in the aggregate; And such absorbing water rates as the sandstone , slate , angle amphibolite ,etc. are greater, contractivity is relatively high. Aggregate grains of foot-path heavy to shrink light inaddition, water content big to shrink the larger. 3, Water gray than. The heavier water consumption is, the higher water and dust are, the concrete shrinks the more greatly. 4, Mix the pharmaceutical outside. It is the better to mix pharmaceutical water-retaining property outside, then the concrete shrinks the smaller. 5, Maintain the method . Water that good maintenance can accelerate the concrete reacts, obtain the intensity of higher concrete. Keep humidity high , low maintaining time to be the longer temperature when maintaining, then the concrete shrinks the smaller. Steam maintain way than maintain way concrete is it take light to shrink naturall. 6, External environment. The humidity is little, the air drying , temperature are high, the wind speed is large in the atmosphere, then the concrete moisture is evaporated fast, the concrete shrinks the faster. 7, Shake and smash the way and time. Machinery shake way of smashing than make firm by ramming or tamping way concrete contractivity take little by hand. Shaking should determine according to mechanical performance to smash time , are generally suitable for 55s / time. It is too short, shake and can not smash closely knit , it is insufficient or not even in intensity to form the concrete; It is too long, cause and divide storey, thick aggregate sinks to the ground floor, the upper strata that the detailed aggregate stays, the intensity is not even , the upper strata incident shrink the crack. And shrink the crack caused to temperature, worthy of constructing the reinforcing bar againing can obviously improve the resisting the splitting of concrete , structure of especially thin wall (thick 200cm of wall ). Mix muscle should is it adopt light diameter reinforcing bar (8 |? construct 14 |? ) to have priority , little interval assign (whether @ 10 construct @ 15cm ) on constructing, the whole section is it mix muscle to be rate unsuitable to be lower than 0 to construct. 3%, can generally adopt 0 . 3%~0. 5%.(4), crack that causes out of shape of plinth of the groundBecause foundation vertical to even to subside or horizontal direction displacement, make the structure produce the additional stress, go beyond resisting the ability of drawing of concrete structure, cause the structure to fracture. The even main reason that subside of the foundation is as follows, 1, Reconnoitres the precision and is not enough for , test the materials inaccuratly in geology. Designing, constructing without fully grasping the geological situation, this is the main reason that cause the ground not to subside evenly .Such as hills area or bridge, district of mountain ridge,, hole interval to be too far when reconnoitring, and ground rise and fall big the rock, reconnoitring the report can't fully reflect the real geological situation . 2, The geological difference of the ground is too large. Building it in the bridge of the valley of the ditch of mountain area, geology of the stream place and place on the hillside change larger, even there are weak grounds in the stream, because the soil of the ground does not causes and does not subside evenly with the compressing. 3, The structure loads the difference too big. Under the unanimous terms, when every foundation too heavy to load difference in geological situation, may cause evenly to subside, for example high to fill out soil case shape in the middle part of the culvert than to is it take heavy to load both sides, to subside soon heavy than both sides middle part, case is it might fracture to contain 4, The difference of basic type of structure is great. Unite it in the bridge the samly , mix and use and does not expand the foundation and a foundation with the foundation, or adopt a foundation when a foot-path or a long difference is great at the same time , or adopt the foundation of expanding when basis elevation is widely different at the same time , may cause the ground not to subside evenly too 5, Foundation built by stages. In the newly-built bridge near the foundation of original bridge, if the half a bridge about expressway built by stages, the newly-built bridge loads or the foundation causes the soil of the ground to consolidate again while dealing with, may cause and subside the foundation of original bridge greatly 6, The ground is frozen bloatedly. The ground soil of higher moisture content on terms that lower than zero degree expands because of being icy; Once temperature goes up , the frozen soil is melted, the setting of ground. So the ground is icy or melts causes and does not subside evenly . 7, Bridge foundation put on body, cave with stalactites and stalagmites, activity fault,etc. of coming down at the bad geology, may cause and does not subside evenly . 8, After the bridge is built up , the condition change of original ground . After most natural grounds and artificial grounds are soaked with water, especially usually fill out such soil of special ground as the soil , loess , expanding in the land ,etc., soil body intensity meet water drop, compress out of shape to strengthen. In the soft soil ground , season causes the water table to drop to draw water or arid artificially, the ground soil layer consolidates and sinks again,reduce the buoyancy on the foundation at the same time , shouldering the obstruction of rubing to increase, the foundation is carried on one's shoulder or back and strengthened .Some bridge foundation is it put too shallow to bury, erode , is it dig to wash flood, the foundation might be moved. Ground load change of terms, bridge nearby is it is it abolish square , grit ,etc. in a large amount to put to pile with cave in , landslide ,etc. reason for instance, it is out of shape that the bridge location range soil layer may be compressed again. So, the condition of original ground change while using may cause and does not subside evenly Produce the structure thing of horizontal thrust to arched bridge ,etc., it is the main reason that horizontal displacement crack emerges to destroy the original geological condition when to that it is unreasonable to grasp incompletely , design and construct in the geological situation.桥梁裂缝产生原因浅析近年来，我省交通基础建设得到迅猛发展，各地建立了大量的混凝土桥梁。
土木工程 外文文献翻译
学院：专业：土木工程姓名：学号：外文出处： Structural Systems to resist (用外文写)Lateral loads附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文抗侧向荷载的结构体系常用的结构体系若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。
确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。
这并不是说没有进行宏观构思的余地。
实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。
如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类：1.抗弯矩框架。
2.支撑框架，包括偏心支撑框架。
3.剪力墙，包括钢板剪力墙。
4.筒中框架。
5.筒中筒结构。
6.核心交互结构。
7. 框格体系或束筒体系。
特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。
而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。
将这些构件结合起来的方法正是高层建筑设计方法的本质。
其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。
这并不是说富于想象力的结构设计就能够创造出伟大建筑。
正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。
无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。
虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。
设计方法的本质贯穿于整个讨论。
设计方法的本质贯穿于整个讨论中。
抗弯矩框架抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。
土木工程外文翻译70683
本科毕业设计（论文）外文翻译译文学生姓名：院 （系）：专业班级：指导教师：完成日期：钢筋混凝土填充框架结构对拆除两个相邻的柱的响应作者： 美国波士顿东北大学，斯奈尔 设计中心收稿日期： 年 月 日，修整后收稿日期 年 月 日，录用日期 年 月 日，网上上传日期 年 月 日。
摘要：本文是评价圣地亚哥旅馆对同时拆除两根相邻的外柱的响应问题，圣地亚哥旅馆是个 层钢筋混凝土填充框架结构。
结构的分析模型应用了有限元法和以此为基础的分析模型来计算结构的整体和局部变形。
分析结果跟实验结果非常吻合。
当测量的竖向位移增加到为四分之一英寸（即 ）的时候，结构就发生连续倒塌。
通过实验分析方法评价和讨论随着柱的移除而产生的变形沿着结构高度上的发展和荷载动态重分配。
讨论了轴向和弯曲的变形传播的不同。
结构横向和纵向的三维桁架在填充墙的参与下被认为是荷载重分配的主要构件。
讨论了两种潜在的脆性破坏模型（没有拉力加强的梁的脆断和有加筋肋的梁的挤出）。
分析评价了结构对额外的重力和无填充墙时的响应。
有限责任公司对此文保留所有权利。
关键词：连续倒塌；荷载重分配；对荷载抵抗能力；动态响应；非线性分析；脆性破坏。
介绍：作为减小由于结构的局部损坏而造成大量伤亡的可能性措施的一部分，美国总务管理局【 】和国防部【 】出台了一系列制度来评价结构对连续倒塌的抵抗力。
【 】定义连续倒塌为，由原始单元的局部破坏在单元间的扩展最终造成结构的整体或不成比例的大部破坏。
通过 和 【 】建议的方法， 定义了两种一般模型来减小结构设计时连续倒塌效应产生的损害，它们分为直接和间接的设计方法。
一般建筑规范和标准用增加结构的整体性的间接设计方法。
间接设计法也应用于美国国防部的降低连续倒塌设计和未归档设备标准中。
尽管间接设计法可以降低连续破坏的风险【 ， 】，对基于此法设计的结构破坏后的表现的判断是不容易实现的。
有一种基于直接设计的方法通过研究瞬间消除受载构件，比如柱子，对结构的影响来评价结构的连续倒塌。
土木工程概论外文翻译.doc
外文原文 2Civil engineering introduction papersAbstract: the civil engineering is a huge discipline, but the main one is building, building whether in China or abroad, has a long history, long-term development process. The world is changing every day, but the building also along with the progress of science and development. Mechanics findings, material of update, ever more scientific technology into the building. But before a room with a tile to cover the top of the house, now for comfort, different ideas, different scientific, promoted the development of civil engineering, making it more perfect.Key words: civil engineering；Architecture；Mechanics；Materials Civil engineering is building various projects collectively. It was meant to be and "military project" corresponding. In English the history of Civil Engineering, mechanical Engineering, electrical Engineering, chemical Engineering belong to Engineering, because they all have Min Yong Xing. Later, as the project development of science and technology, mechanical, electrical, chemical has gradually formed independent scientific, to Engineering became Civil Engineering of specialized nouns. So far, in English, to Engineering include water conservancy project, port engineering, while in our country, water conservancy projects and port projects also become very close and civil engineering relatively independent branch. Civil engineering construction of object, both refers to that built on the ground, underground water engineering facilities, also refers to applied materials equipment and conduct of the investigation, design and construction, maintenance, repair and other professional technology.Civil engineering is a kind of with people's food, clothing, shelter and transportation has close relation of the project. Among them with "live" relationship is directly. Because, to solve the "live" problem，must build various types of buildings. To solve the "line, food and clothes" problem both direct side, but also a indirect side. "Line", must build railways, roads, Bridges, "Feed", must be well drilling water, water conservancy, farm irrigation, drainage water supply for the city that is direct relation. Indirectly relationship is no matter what you do, manufacturing cars, ships, or spinning and weaving, clothing, or even production steel, launch satellites, conducting scientific research activities are inseparable from build various buildings, structures and build all kinds of project facilities.Civil engineering with the progress of human society and development, yet has evolved into large-scale comprehensive discipline, it has out many branch, such as: architectural engineering, the railway engineering, road engineering, bridge engineering, special engineering structure, water and wastewater engineering, port engineering, hydraulic engineering, environment engineering disciplines. [1] Civil engineering as an important basic disciplines, and has its important attributes of: integrated, sociality, practicality, unity. Civil engineering for the development of national economy and the improvement of people's life provides an important material and technical basis, for many industrial invigoration played a role in promoting, engineering construction is the formation of a fixed asset basic production process, therefore, construction and real estate become in many countries and regions, economic powerhouses.Construction project is housing planning, survey, design, construction of the floorboard. Purpose is for human life and production provide places.Houses will be like a man, it's like a man's life planning environment is responsible by the planners, Its layout and artistic processing, corresponding to the body shape looks and temperament, is responsible by the architect, Its structure is like a person's bones and life expectancy, the structural engineer is responsible, Its water, heating ventilation and electrical facilities such as the human organ and the nerve, is by the equipment engineer is responsible for. Also like nature intact shaped like people, in the city I district planning based on build houses, and is the construction unit, reconnaissance unit, design unit of various design engineers and construction units comprehensive coordination and cooperation process.After all, but ，is structural stress body reaction force and the internal stress and how external force balance. Building to tackle, also must solve the problem is mechanical problems. We have to solve the problem of discipline called architectural mechanics. Architectural mechanics have can be divided into: statics, material mechanics and structural mechanics three mechanical system. Architectural mechanics is discussion and research building structure and component in load and other factors affecting the working condition of, also is the building of intensity, stiffness and stability. In load, bear load and load of structure and component can cause the surrounding objects in their function, and the object itself by the load effect and deformation, and there is the possibility of damage, but the structure itself has certain resistance to deformation and destruction of competence, and the bearingcapacity of the structure size is and component of materials, cross section, and the structural properties of geometry size, working conditions and structure circumstance relevant. While these relationships can be improved by mechanics formula solved through calculation.Building materials in building and has a pivotal role. Building material is with human society productivity and science and technology improves gradually developed. In ancient times, the human lives, the line USES is the rocks and trees. The 4th century BC, 12 ~ has created a tile and brick, humans are only useful synthetic materials made of housing. The 17th century had cast iron and Sheltie later, until the eighteenth century had Portland cement, just make later reinforced concrete engineering get vigorous development. Now all sorts of high-strength structural materials, new decoration materials and waterproof material development, criterion and 20th century since mid organic polymer materials in civil engineering are closely related to the widely application. In all materials, the most main and most popular is steel, concrete, lumber, masonry. In recent years, by using two kinds of material advantage, will make them together, the combination of structure was developed. Now, architecture, engineering quality fit and unfit quality usually adopted materials quality, performance and using reasonable or not have direct connection, in meet the same technical indicators and quality requirements, under the precondition of choice of different material is different, use method of engineering cost has direct impact.In construction process, building construction is and architectural mechanics, building materials also important links. Construction is to the mind of the designer, intention and idea into realistic process, from the ancient JuChao place to now skyscrapers, from rural to urban country road elevated road all need through "construction" means. A construction project, including many jobs such as dredging engineering, deep foundation pit bracing engineering, foundation engineering, reinforced concrete structure engineering, structural lifting project, waterproofing, decorate projects, each type of project has its own rules, all need according to different construction object and construction environment conditions using relevant construction technology, in work-site. whenever while, need and the relevant hydropower and other equipment composition of a whole, each project between reasonable organizing and coordination, better play investment benefit. Civil engineering construction in the benefit, while also issued by the state in strict accordance with the relevant construction technology standard, thus further enhanceChina's construction level to ensure construction quality, reduce the cost for the project.Any building built on the surface of the earth all strata, building weight eventually to stratum, have to bear. Formation Support building the rocks were referred to as foundation, and the buildings on the ground and under the upper structure of self-respect and liable to load transfer to the foundation of components or component called foundation. Foundation, and the foundation and the superstructure is a building of three inseparable part. According to the function is different, but in load, under the action of them are related to each other, is the interaction of the whole. Foundation can be divided into natural foundation and artificial foundation, basic according to the buried depth is divided into deep foundation and shallow foundation. , foundation and foundation is the guarantee of the quality of the buildings and normal use close button, where buildings foundation in building under loads of both must maintain overall stability and if the settlement of foundation produce in building scope permitted inside, and foundation itself should have sufficient strength, stiffness and durability, also consider repair methods and the necessary foundation soil retaining water and relevant measures. [3]As people living standard rise ceaselessly, the people to their place of building space has become not only from the number, and put forward higher requirement from quality are put car higher demands that the environment is beautiful, have certain comfort. This needs to decorate a building to be necessary. If architecture major engineering constitutes the skeleton of the building, then after adornment building has become the flesh-and-blood organism, final with rich, perfect appearance in people's in front, the best architecture should fully embody all sorts of adornment material related properties, with existing construction technology, the most effective gimmick, to achieve conception must express effect. Building outfit fix to consider the architectural space use requirement, protect the subject institutions from damage, give a person with beautiful enjoying, satisfy the requirements of fire evacuation, decorative materials and scheme of rationality, construction technology and economic feasibility, etc. Housing construction development and at the same time, like housing construction as affecting people life of roads, Bridges, tunnels has made great progress.In general civil engineering is one of the oldest subjects, it has made great achievements, the future of the civil engineering will occupy in people's life moreimportant position. The environment worsening population increase, people to fight for survival, to strive for a more comfortable living environment, and will pay more attention to civil engineering. In the near future, some major projects estimated to build, insert roller skyscrapers, across the ocean Bridges, more convenient traffic would not dream. The development of science and technology, and the earth is deteriorating environment will be prompted civil engineering to aerospace and Marine development, provide mankind broader space of living. In recent years, engineering materials mainly is reinforced concrete, lumber and brick materials, in the future, the traditional materials will be improved, more suitable for some new building materials market; especially the chemistry materials will promote the construction of towards a higher point. Meanwhile, design method of precision, design work of automation, information and intelligent technology of introducing, will be people have a more comfortable living environment. With the development of the theory and new materials, the emergence of the application of computer, high-tech introduction to wait to will make civil engineering have a new leap.This is a door needs calm and a great deal of patience and attentive professional. Because hundreds of thousands, even thousands of thousands of lines to building each place structure clearly reflected. Without a gentle state of mind, do what thing just floating on the surface, to any a building structure, to be engaged in business and could not have had a clear, accurate and profound understanding of, the nature is no good. In this business, probably not burn the midnight oil of courage, not to reach the goal of spirit not to give up, will only be companies eliminated.This is a responsible and caring industry. Should have a single responsible heart - I one's life in my hand, thousands of life in my hand. Since the civil, should choose dependably shoulder the responsibility.Finally, this is a constant pursuit of perfect industry. Pyramid, spectacular now: The Great Wall, the majestic... But if no generations of the pursuit of today, we may also use the sort of the oldest way to build this same architecture. Design a building structure is numerous, but this is all experienced centuries of clarification, through continuous accumulation, keep improving, innovation obtained. And such pursuit, not confined in the past. Just think, if the design of a building can be like calculation one plus one equals two as simple and easy to grasp, that was not for what? Therefore, a civil engineer is in constant of in formation. One of the most simple structure, theleast cost, the biggest function. Choose civil, choosing a steadfast diligence, innovation, pursuit of perfect path.Reference:[1] LuoFuWu editor. Civil engineering (professional). Introduction to wuhan. Wuhan university of technology press. 2007[2] WangFuChuan, palace rice expensive editor. Construction engineering materials. Beijing. Science and technology literature press. 2002.[3] jiang see whales, zhiming editor. Civil engineering introduction of higher education press. Beijing, 1992.中文翻译2土木工程概论摘要：土木工程是一门庞大大学科，主要的部分是建筑，无论在国内还是在国外，都有着悠久的历史发展过程。
土木工程专业毕业设计外文翻译
Building construction concrete crack of prevention and processingAbstractThe crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing ForewordConcrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering. Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and antiShen ability, influence building of external appearance, service life, severity will threat arrive people's life and property safety.A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that.Modern age science research with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside.The reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of width.But at under construction should as far as possible adopt a valid measure control crack creation, make the structure don't appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus. Concrete crack creation of the reason be a lot of and have already transformed to cause of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reason cause of crack;Have outside carry the crack that the function cause;Protected environment not appropriate the crack etc. caused with chemical effect.Want differentiation to treat in the actual engineering, work°out a problem according to the actual circumstance. In the concrete engineering the familiar crack and the prevention 1.Stem Suo crack and prevention Stem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week.In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't negative.Stem Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result:The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pullshould dint but creation crack.The relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy creation.Stem the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0.2 mm, the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short to distribute.Stem Suo crack usually the anti- Shen of influence concrete, cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant. Main prevention measure:While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement.Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water.Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can't big in match ratio design give settle of use water quantity.Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time.Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect.Five is a constitution the accommodation is in the concrete structure of the constringency sew. 2.The Su constringency crack and prevention Su constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent appearance.Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 mm.It creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning very small, perhaps concrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again can't resist itsconstringency, therefore creation cracked.The influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature, wind velocity, relative humidity……etc.. Main prevention measure:One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire.Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of dosage.Three is to sprinkle before building concrete, water basic level and template even to soak through.Four is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface.Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time. 3.Sink to sink crack and prevention The creation which sink to sink crack is because of the structure foundation soil quality not and evenly, loose soft or return to fill soil dishonest or soak in water but result in theasymmetry sink to decline with the result that;Perhaps because of template just degree shortage, the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the template prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation crack.This kind crack many is deep enter or pierce through sex crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or present 30 °s-45 °Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion relation.Crack width under the influence of temperature variety smaller.The foundation after transform stability sink to sink crack also basic tend in stability. Main prevention measure:One is rightness loose soft soil, return to fill soil foundation a construction at the upper part structure front should carry on necessity of Hang solid with reinforce.Two is the strength that assurance template is enough andjust degree, and prop up firm, and make the foundation be subjected to dint even.Three is keep concrete from sprinkle infusing the foundation in the process is soak by water.Four is time that template tore down to can't be too early, and want to notice to dismantle a mold order of sequence.Five is at jelly soil top take to establish template to notice to adopt certain of prevention measure. 4.Temperature crack and prevention Temperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete compare the earth area of the concrete structure.Concrete after sprinkling to build, in the hardening the process, cement water turn a creation a great deal of of water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, each sign square the rice concrete will release a calories of 17500-27500 kJ and make concrete internal thus the temperature rise to reach to 70 ℃or so even higher)Because the physical volume of concrete be more big, a great deal of of water turn hot accumulate at the concrete inner part but not easy send forth, cause inner part the temperature hoick, but the concrete surface spread hot more quick, so formation inside outside of bigger difference in temperature, the bigger difference in temperature result in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull should dint.When pull should dint exceed the anti- of concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction period.In the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc., will cause concrete surface the temperature sharply descend, but creation constringency, surface constringency of the concrete be subjected to inner part concrete of control, creation very big of pull should dint but creation crack, this kind of crack usually just in more shallow scope of the concrete surface creation. The alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;The size bigger structure of the beam plank length, the crack run parallel with short side more;Thorough with pierce through sex of temperature crack general and short side direction parallelism or closeparallelism, crack along long side cent the segment appear, in the center more airtight.Crack width the size be different, be subjected to temperature variety influence more obvious, winter compare breadth, summer more narrow.The concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin, but cold Suo crack of thick thin variety not too obvious.The emergence of the this kind crack will cause the rust eclipse of reinforcing bar, the carbonization of concrete, the anti- jelly which lower concrete melt, anti- tired and anti- Shenability etc.. Main prevention measure:One is as far as possible choose to use low hot or medium hot water mire, like mineral residue cement, powder ash from stove cement……etc..Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450 kg/m 3 following.Three is to lower water ash ratio, water ash of the general concrete ratio control below 0.6.Four is improvement the bone anticipate class to go together with, the Chan add powder ash from stove or efficiently reduce water etc. to come to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lower sprinkle of concrete to build temperature.Six is the in addition that the Chan add a have of fixed amount to reduce water and increase Su, slow Ning etc. function in the concrete, improvement the concrete mix to match a thing of mobility, protect water, lower water to turn hot, postpone hot Feng of emergence time.Seven is the heat season sprinkle to build can the adoption take to establish to hide sun plank etc. assistance measure control concrete of Wen Sheng, lowBuilding construction concrete crack of prevention and processingAbstractThe crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing ForewordConcrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering. Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and antiShen ability, influence building of external appearance, service life, severity will threat arrive people's life and property safety.A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that.Modern age science research with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside.The reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of width.But at under construction should as far as possible adopt a valid measure control crack creation, make the structure don't appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus. Concrete crack creation of the reason be a lot of and have already transformed to cause of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reason cause ofcrack;Have outside carry the crack that the function cause;Protected environment not appropriate the crack etc. caused with chemical effect.Want differentiation to treat in the actual engineering, work°out a problem according to the actual circumstance. In the concrete engineering the familiar crack and the prevention 1.Stem Suo crack and prevention Stem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week.In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't negative.Stem Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result:The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pull should dint but creation crack.The relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy creation.Stem the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0.2 mm, the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short to distribute.Stem Suo crack usually the anti- Shen of influence concrete, cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant. Main prevention measure:While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement.Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water.Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can't big in match ratio design give settle of use water quantity.Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time.Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect.Five is a constitution the accommodation is in the concrete structure of the constringency sew. 2.The Su constringency crack and prevention Su constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent appearance.Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 mm.It creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning very small, perhaps concrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again can't resist itsconstringency, therefore creation cracked.The influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature,wind velocity, rela tive humidity……etc.. Main prevention measure:One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire.Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of dosage.Three is to sprinkle before building concrete, water basic level and template even to soak through.Four is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface.Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time. 3.Sink to sink crack and prevention The creation which sink to sink crack is because of the structure foundation soil quality not and evenly, loose soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to decline with the result that;Perhaps because of template just degree shortage, the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the template prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation crack.This kind crack many is deep enter or pierce through sex crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or present 30 °s-45 °Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion relation.Crack width under the influence of temperature variety smaller.The foundation after transform stability sink to sink crack also basic tend in stability. Main prevention measure:One is rightness loose soft soil, return to fill soil foundation a construction at the upper part structure front should carry on necessity of Hang solid with reinforce.Two is the strength that assurance template is enough andjust degree, and prop up firm, and make the foundation be subjected to dint even.Three is keep concrete from sprinkle infusing the foundation in the process is soak by water.Four is time that template tore down to can't be too early, and want to notice to dismantle a mold order of sequence.Five is at jelly soil top take to establish template to notice to adopt certain of prevention measure. 4.Temperature crack and prevention Temperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete compare the earth area of the concrete structure.Concrete after sprinkling to build, in the hardening the process, cement water turn a creation a great deal of of water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, each sign square the rice concrete will release a calories of 17500-27500 kJ and make concrete internal thus the temperature rise to reach to 70 ℃or so even higher)Because the physical volume of concrete be more big, a great deal of of water turn hot accumulate at the concrete inner part but not easy send forth, cause inner part the temperature hoick, but the concrete surface spread hot more quick, so formation inside outside of bigger difference in temperature, the bigger difference in temperature result in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull should dint.When pull should dint exceed the anti- of concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction period.In the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc., will cause concrete surface the temperature sharply descend, but creation constringency, surface constringency of the concrete be subjected to inner part concrete of control, creation very big of pull should dint but creation crack, this kind of crackusually just in more shallow scope of the concrete surface creation. The alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;The size bigger structure of the beam plank length, the crack run parallel with short side more;Thorough with pierce through sex of temperature crack general and short side direction parallelism or closeparallelism, crack along long side cent the segment appear, in the center more airtight.Crack width the size be different, be subjected to temperature variety influence more obvious, winter compare breadth, summer more narrow.The concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin, but cold Suo crack of thick thin variety not too obvious.The emergence of the this kind crack will cause the rust eclipse of reinforcing bar, the carbonization of concrete, the anti- jelly which lower concrete melt, anti- tired and anti- Shen ability etc.. Main prevention measure:One is as far as possible choose to use low hot or medium hot water mire, like mineral residue cement, powder ash from stove cement……etc..Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450 kg/m 3 following.Three is to lower water ash ratio, water ash of the general concrete ratio control below 0.6.Four is improvement the bone anticipate class to go together with, the Chan add powder ash from stove or efficiently reduce water etc. to come to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lower sprinkle of concrete to build temperature.Six is the in addition that the Chan add a have of fixed amount to reduce water and increase Su, slow Ning etc. function in the concrete, improvement the concrete mix to match a thing of mobility, protect water, lower water to turn hot, postpone hot Feng of emergence time.Seven is the heat season sprinkle to build can the adoption take to establish to hide sun plank etc. assistance measure control concrete of Wen Sheng, lower to sprinkle temperature of build the concrete.Eight is the temperature of big physical volume concrete should the dint relate to structure size, concrete structure size more big, temperature should dint more big, so want reasonable arrangement construction work preface, layering, cent the piece sprinkle to build, for the convenience of in spread hot, let up control.Nine is at great inner part constitution of the physical volume concrete cool off piping, cold water perhaps cold air cool off, let up concrete of inside outside difference in temperature.Ten is the supervision which strengthen concrete temperature, adopt to cool off in time, protection measure.11 is to reserve temperature constringency to sew.12 is to let up to control, sprinkle proper before building concrete in the Ji rock and old concrete top build a 5 mm or so sand mat a layer or usage asphalt etc. material Tu2 Shua.13 is to strengthen concrete to protect, the concrete after sprinkle build use moist grass Lian in time, hemp slice's etc. overlay, and attention sprinkle water to protect, appropriate extension protect time, assurance the concrete surface be slow-moving cool off.At the cold season, concrete surface should constitution heat preservation measure, in order to prevent cold wave assault.14 is the allocation be a little amount in the concrete of reinforcing bar perhaps add fiber material concrete of temperature crack control at certain of scope inside. 5.Crack and prevention that the chemical reaction cause Alkali bone's anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the reinforced concrete structure of because of chemical reaction but cause of crack. The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open crack.In this kind of crack general emergence concrete structure usage。
土木工程专业外文翻译--土木工程
外文原文：Civil EngineeringCivil engineering is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket launching facilities.Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airport, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to self-contained communities.The word civil derives from the Latin for citizen. In 1782, Englishman John Seaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineer has often been used to refer to engineers who build public facilities, although the field is much broader.Scope Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills pf many kinds of civil engineer specialties may be needed. When a project begins, the site is surveyed and mapped by civil engineers who experiment to determine if the earth can bear the weight of project. Environmental specialists study the project’s impact on the local area, the potential for air and groundwater pollution, the project’s impact on local animal and plant life, and how the project can be designed to meet government requirements aimed at protecting the environment. Transportation specialists determine what kind of facilities are needed to ease the burden on local roads and other transportation networks that will result from the completed project. Meanwhile, structural specialists raise preliminary data to make detailed designs, plans, and specifications for the project. Supervising and coordinating the work of these civil engineer specialists, from beginning to end of the project, are the construction management specialists. Based on information supplied by the other specialists, construction management civil engineers estimate quantitiesand costs of materials and subcontractors, and perform other supervisory work to ensure the project is completed on time and as specified.Many civil engineers, among them the top people in the field, work in design. As we have seen, civil engineers work on many different kinds of structures, so it is normal practice for an engineer to specialize in just one kind. In designing buildings, engineers often work as consultants to architectural or construction firms. Dams, bridges, water supply systems, and other large projects ordinarily employ several engineers whose work is coordinated by a system engineer who is in charge of the entire project. In many cases, engineers from other disciplines are involved. In a dam project, for example, electrical and mechanical engineers work on the design of the powerhouse and its equipment. In other cases, civil engineers are assigned to work on a project in another field; in the space program, for instance, civil engineers were necessary in the design and construction of such structures as launching pads and rocket storage facilities.Throughout any given project, civil engineers make extensive use of computers. Computes are used to design the project’s various elements (computer-aided design, or CAD) and to manger it. Computers are a necessity for the modern civil engineer because they permit the engineer to efficiently handle the large quantities of data needed in determining the best way to construct a project.Structural engineering In this specialty, civil engineers plan and design structures of all types, including bridges dams, power plants, supports for equipment, special structures for offshore projects, the United States space program, transmission towers, giant astronomical and radio telescopes, and many other kinds of projects.Using computers, structural engineers determine the forces a structure must resist, its own weight, wind and hurricane forces temperature changes that expand or contract construction materials, and earthquakes. They also determine the combination of appropriate materials: steel, concrete, plastic, stone, asphalt, brick, aluminum, or other construction materials.Water resources engineering Civil engineers in this specialty deal with all aspects of the physical control of water. Their projects help prevent floods, supply water for cities and for irrigation, manage and control rivers and water runoff, and maintain beaches and other waterfront facilities. In addition, they design and maintain harbors, canals, and locks, build huge hydroelectric dams and smaller dams and water impoundments of all kinds, help design offshorestructures, and determine the location of structures affecting navigation.Geotechnical engineering Civil engineers who specialize in this filed analyze the properties of soils and rocks that support structures and affect structural behavior. They evaluate and work to minimize the potential settlement of buildings and other structures that stems from the pressure of their weight on the earth. These engineers also evaluate and determine how to strengthen the stability of slopes and how to protect structures against earthquakes and the effects of groundwater.Environmental engineering In this branch of engineering, civil engineers design, build, and supervise systems to provide safe drinking water and to prevent and control pollution of water supplies, both on the surface and underground. They also design, build, and supervise projects to control or eliminate pollution of the land and air. These engineers build water and wastewaters treatment plants, and design air scrubbers and other devices to minimize or eliminate air pollution caused by industrial processes, incineration, or other smoke-producing activities. They also work to control toxic and hazardous wastes through the construction of special dump sites or the neutralizing of toxic and hazardous substances. In addition the engineers design and manage sanitary landfills to prevent pollution of surrounding land.Transportation engineering Civil engineers working in this specialty build facilities to ensure safe and efficient movement of both people and goods. They specialize in designing and maintaining all types of transportation facilities, highways and streets, mass transit systems, railroads and airfields ports and harbors. Transportation engineers apply technological knowledge as well as consideration of the economic, political, and social factors in designing each project. They work closely with urban planners since the quality of the community is directly related to the quality of the transportation system.Pipeline engineering In this branch of civil engineering, engineers build pipelines and related facilities, which transport liquids, gases, or solids ranging from coal slurries (mixed coal and water) and semi liquids wastes, to water, oil and various types pf highly combustible and noncombustible gases. The engineers determine pipeline design, the economic and environmental impact of a project on regions it must traverse, the type pf materials to be used-steel, concrete, plastic, or combinations of various materials, installation techniques, methods for testing pipeline strength, and controls for maintaining proper pressure and rate of flow of materials being transported. When hazardous materials are being carried, safety is a major consideration as well.Construction engineering Civil engineers in this field oversee the construction of a project from beginning to end. Sometimes called project engineers, they apply both technical and managerial skills, including knowledge of construction methods, planning, organizing, financing, and operating construction projects. They coordinate the activities of virtually everyone engaged in the work: the surveyors, workers who lay out and construct the temporary roads and ramps, excavate for the foundation, build the forms and pour the concrete; and workers who build the steel frame-work. These engineers also make regular progress reports to the owners of the structure.Construction is a complicated process on almost all engineering projects. It involves scheduling the work and utilizing the equipment and the materials so that coats are kept as low as possible. Safety factor must also be taken into account, since construction can be very dangerous. Many civil engineers therefore specialize in the construction phase.Community and urban planning Those engaged in this area of civil engineering may plan and develop communities within a city, or entire cities. Such planning involves far more than engineering considerations; environmental, social, and economic factors in the use and development of land and natural resources are also key elements. They evaluate the kinds of facilities needed, including streets and highways, public transportation systems, airports, and recreational and other facilities to ensure social and economic as well as environmental well-being.Photogrammetry, surveying, and mapping The civil engineers in this specialty precisely measure the Earth’s surface to obtain reliable information for locating and designing engineering projects. This practice often involves high-technology methods such as satellite and aerial surveying, and computer processing of photographic imagery. Radio signals from satellites, scanned by laser and sonic beams, are converted to maps to provide very accurate measurements for boring tunnels, building highways and dams, plotting flood control and irrigation projects, locating subsurface geologic formations that may affect a construction project and a host of other building uses.Other specialties Three additional civil engineering specialties that are not entirely within the scope of civil engineering teaching.Engineering research Research is one of the most important aspects of scientific and engineering practice. A researcher usually works as a member of a team with other scientists and engineers. He or she is often employed in alaboratory that financed by government or industry. Areas of research connected with civil engineering include soil mechanics and soil stabilization techniques, and also the development and testing of new structural materials.Engineering management Many civil engineers choose careers that eventually lead to management. Others are also to start their careers in management positions. The civil engineer manager combines technical knowledge with an ability to organize and coordinate worker power, materials, machinery, and money. These engineers may work in government municipal, county, state, or federal; in the U.S.Army Corps of Engineers as military or civilian management engineers; or in semiautonomous regional or city authorities or similar organization. They may also manage private engineering firms ranging in size from a few employees to hundreds.Engineering teaching The civil engineer who chooses a teaching career usually teaches both graduate and undergraduate students in technical specialties. Many teaching civil engineers engage in basic research that eventually leads to technical innovations in construction materials and methods. Many also serve as consultants on engineering projects, or on technical boards and commissions associated with major projects.中文译文：土木工程土木工程是指对建成环境的规划、设计、建造、管理等一系列活动。
土木工程 外文翻译 外文文献 英文文献
一、外文原文Talling building and Steel construction Although there have been many advancements in building construction technology in general. Spectacular archievements have been made in the design and construction of ultrahigh-rise buildings.The early development of high-rise buildings began with structural steel framing.Reinforced concrete and stressed-skin tube systems have since been economically and competitively used in a number of structures for both residential and commercial purposes.The high-rise buildings ranging from 50 to 110 stories that are being built all over the United States are the result of innovations and development of new structual systems.Greater height entails increased column and beam sizes to make buildings more rigid so that under wind load they will not sway beyond an acceptable limit.Excessive lateral sway may cause serious recurring damage to partitions,ceilings.and other architectural details. In addition,excessive sway may cause discomfort to the occupants of the building because their perception of such motion.Structural systems of reinforced concrete,as well as steel,take full advantage of inherent potential stiffness of the total building and therefore require additional stiffening to limit the sway.In a steel structure,for example,the economy can be defined in terms of the total average quantity of steel per square foot of floor area of the building.Curve A in Fig .1 represents the average unit weight of a conventional frame with increasing numbers of stories. Curve B represents the average steel weight if the frame is protected from all lateral loads. The gap between the upper boundary and the lower boundary represents the premium for height for the traditional column-and-beam frame.Structural engineers have developed structural systems with a view to eliminating this premium.Systems in steel. Tall buildings in steel developed as a result ofseveral types of structural innovations. The innovations have been applied to the construction of both office and apartment buildings.Frame with rigid belt trusses. In order to tie the exterior columns of a frame structure to the interior vertical trusses,a system of rigid belt trusses at mid-height and at the top of the building may be used. A good example of this system is the First Wisconsin Bank Building(1974) in Milwaukee.Framed tube. The maximum efficiency of the total structure of a tall building, for both strength and stiffness,to resist wind load can be achieved only if all column element can be connected to each other in such a way that the entire building acts as a hollow tube or rigid box in projecting out of the ground. This particular structural system was probably used for the first time in the 43-story reinforced concrete DeWitt Chestnut Apartment Building in Chicago. The most significant use of this system is in the twin structural steel towers of the 110-story World Trade Center building in New York Column-diagonal truss tube. The exterior columns of a building can be spaced reasonably far apart and yet be made to work together as a tube by connecting them with diagonal members interesting at the centre line of the columns and beams. This simple yet extremely efficient system was used for the first time on the John Hancock Centre in Chicago, using as much steel as is normally needed for a traditional 40-story building.Bundled tube. With the continuing need for larger and taller buildings, the framed tube or the column-diagonal truss tube may be used in a bundled form to create larger tube envelopes while maintaining high efficiency. The 110-story Sears Roebuck Headquarters Building in Chicago has nine tube, bundled at the base of the building in three rows. Some of these individual tubes terminate at different heights of the building, demonstrating the unlimited architectural possibilities of this latest structural concept. The Sears tower, at a height of 1450 ft(442m), is the world’s tallest building.Stressed-skin tube system. The tube structural system was developed for improving the resistance to lateral forces (wind and earthquake) and thecontrol of drift (lateral building movement ) in high-rise building. The stressed-skin tube takes the tube system a step further. The development of the stressed-skin tube utilizes the façade of the building as a structural element which acts with the framed tube, thus providing an efficient way of resisting lateral loads in high-rise buildings, and resulting in cost-effective column-free interior space with a high ratio of net to gross floor area.Because of the contribution of the stressed-skin façade, the framed members of the tube require less mass, and are thus lighter and less expensive. All the typical columns and spandrel beams are standard rolled shapes,minimizing the use and cost of special built-up members. The depth requirement for the perimeter spandrel beams is also reduced, and the need for upset beams above floors, which would encroach on valuable space, is minimized. The structural system has been used on the 54-story One Mellon Bank Center in Pittburgh.Systems in concrete. While tall buildings constructed of steel had an early start, development of tall buildings of reinforced concrete progressed at a fast enough rate to provide a competitive chanllenge to structural steel systems for both office and apartment buildings.Framed tube. As discussed above, the first framed tube concept for tall buildings was used for the 43-story DeWitt Chestnut Apartment Building. In this building ,exterior columns were spaced at 5.5ft (1.68m) centers, and interior columns were used as needed to support the 8-in . -thick (20-m) flat-plate concrete slabs.Tube in tube. Another system in reinforced concrete for office buildings combines the traditional shear wall construction with an exterior framed tube. The system consists of an outer framed tube of very closely spaced columns and an interior rigid shear wall tube enclosing the central service area. The system known as the tube-in-tube system , made it possible to design the world’s present tallest (714ft or 218m)lightweight concrete bu ilding( the 52-story One Shell Plaza Building in Houston) for the unit price of a traditional shear wall structure of only 35 stories.Systems combining both concrete and steel have also been developed, an examle of which is the composite system developed by skidmore, Owings &Merril in which an exterior closely spaced framed tube in concrete envelops an interior steel framing, thereby combining the advantages of both reinforced concrete and structural steel systems. The 52-story One Shell Square Building in New Orleans is based on this system.Steel construction refers to a broad range of building construction in which steel plays the leading role. Most steel construction consists of large-scale buildings or engineering works, with the steel generally in the form of beams, girders, bars, plates, and other members shaped through the hot-rolled process. Despite the increased use of other materials, steel construction remained a major outlet for the steel industries of the U.S, U.K, U.S.S.R, Japan, West German, France, and other steel producers in the 1970s.二、原文翻译高层结构与钢结构近年来，尽管一般的建筑结构设计取得了很大的进步，但是取得显著成绩的还要属超高层建筑结构设计。
土木工程--外文文献翻译
土木工程--外文文献翻译-CAL-FENGHAI.-(YICAI)-Company One1学院：专业：土木工程姓名：学号：外文出处： Structural Systems to resist (用外文写)Lateral loads附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文抗侧向荷载的结构体系常用的结构体系若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。
确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。
这并不是说没有进行宏观构思的余地。
实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。
如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类：1.抗弯矩框架。
2.支撑框架，包括偏心支撑框架。
3.剪力墙，包括钢板剪力墙。
4.筒中框架。
5.筒中筒结构。
6.核心交互结构。
7. 框格体系或束筒体系。
特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。
而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。
将这些构件结合起来的方法正是高层建筑设计方法的本质。
其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。
这并不是说富于想象力的结构设计就能够创造出伟大建筑。
正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。
无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。
虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。
设计方法的本质贯穿于整个讨论。
土木工程外文翻译-原文
外文原文Response of a reinforced concrete infilled-frame structure to removal of twoadjacent columnsMehrdad Sasani_Northeastern University, 400 Snell Engineering Center, Boston, MA 02115, UnitedStatesReceived 27 June 2007; received in revised form 26 December 2007; accepted 24January 2008Available online 19 March 2008AbstractThe response of Hotel San Diego, a six-story reinforced concrete infilled-frame structure, is evaluated following the simultaneous removal of two adjacent exterior columns. Analytical models of the structure using the Finite Element Method as well as the Applied Element Method are used to calculate global and local deformations. The analytical results show good agreement with experimental data. The structure resisted progressive collapse with a measured maximum vertical displacement of only one quarter of an inch (6.4 mm). Deformation propagation over the height of the structure and the dynamic load redistribution following the column removal are experimentally and analytically evaluated and described. The difference between axial and flexural wave propagations is discussed. Three-dimensional Vierendeel (frame) action of the transverse and longitudinal frames with the participation of infill walls is identified as the major mechanism for redistribution of loads in the structure. The effects of two potential brittle modes of failure (fracture of beam sections without tensile reinforcement and reinforcing bar pull out) are described. The response of the structure due to additional gravity loads and in the absence of infill walls is analytically evaluated.c 2008 Elsevier Ltd. All rights reserved.Keywords: Progressive collapse; Load redistribution; Load resistance; Dynamic response; Nonlinear analysis; Brittle failure1.IntroductionThe principal scope of specifications is to provide general principles and computation al methods in order to verify safety of structures. The “ safety factor ”, which accor ding to modern trends is independent of the nature and combination of the materials u sed, can usually be defined as the ratio between the conditions. This ratio is also prop ortional to the inverse of the probability ( risk ) of failure of the structure.Failure has to be considered not only as overall collapse of the structure but also as un serviceability or, according to a more precise. Common definition. As the reaching of a “ limit state ” which causes the construction not to accomplish the task it was desi gned for. There are two categories of limit state :(1)Ultimate limit sate, which corresponds to the highest value of the load-bearing cap acity. Examples include local buckling or global instability of the structure; failure of some sections and subsequent transformation of the structure into a mechanism; failure by fatigue; elastic or plastic deformation or creep that cause a substantial change of t he geometry of the structure; and sensitivity of the structure to alternating loads, to fire and to explosions.(2)Service limit states, which are functions of the use and durability of the structure. E xamples include excessive deformations and displacements without instability; early o r excessive cracks; large vibrations; and corrosion.Computational methods used to verify structures with respect to the different safety co nditions can be separated into:(1)Deterministic methods, in which the main parameters are considered as nonrandom parameters.(2)Probabilistic methods, in which the main parameters are considered as random para meters.Alternatively, with respect to the different use of factors of safety, computational meth ods can be separated into:(1)Allowable stress method, in which the stresses computed under maximum loads are compared with the strength of the material reduced by given safety factors.(2)Limit states method, in which the structure may be proportioned on the basis of its maximum strength. This strength, as determined by rational analysis, shall not be less than that required to support a factored load equal to the sum of the factored live load and dead load ( ultimate state ).The stresses corresponding to working ( service ) conditions with unfactored live and dead loads are compared with prescribed values ( service limit state ) . From the four possible combinations of the first two and second two methods, we can obtain some u seful computational methods. Generally, two combinations prevail:(1)deterministic methods, which make use of allowable stresses. (2)Probabilistic meth ods, which make use of limit states.The main advantage of probabilistic approaches is that, at least in theory, it is possible to scientifically take into account all random factors of safety, which are then combin ed to define the safety factor. probabilistic approaches depend upon :(1) Random distribution of strength of materials with respect to the conditions of fabri cation and erection ( scatter of the values of mechanical properties through out the str ucture ); (2) Uncertainty of the geometry of the cross-section sand of the structure ( fa ults and imperfections due to fabrication and erection of the structure );(3) Uncertainty of the predicted live loads and dead loads acting on the structure; (4)U ncertainty related to the approximation of the computational method used ( deviation of the actual stresses from computed stresses ). Furthermore, probabilistic theories me an that the allowable risk can be based on several factors, such as :(1) Importance of the construction and gravity of the damage by its failure; (2)Numbe r of human lives which can be threatened by this failure; (3)Possibility and/or likeliho od of repairing the structure; (4) Predicted life of the structure. All these factors are rel ated to economic and social considerations such as：(1) Initial cost of the construction;(2) Amortization funds for the duration of the construction;(3) Cost of physical and material damage due to the failure of the construction;(4) Adverse impact on society;(5) Moral and psychological views.The definition of all these parameters, for a given safety factor, allows constructio n at the optimum cost. However, the difficulty of carrying out a complete probabilistic analysis has to be taken into account. For such an analysis the laws of the distribution of the live load and its induced stresses, of the scatter of mechanical properties of mat erials, and of the geometry of the cross-sections and the structure have to be known. F urthermore, it is difficult to interpret the interaction between the law of distribution of strength and that of stresses because both depend upon the nature of the material, on t he cross-sections and upon the load acting on the structure. These practical difficulties can be overcome in two ways. The first is to apply different safety factors to the mate rial and to the loads, without necessarily adopting the probabilistic criterion. The seco nd is an approximate probabilistic method which introduces some simplifying assump tions ( semi-probabilistic methods ) . As part of mitigation programs to reduce the likelihood of mass casualties following local damage in structures, the General Services Administration [1] and the Department of Defense [2] developed regulations to evaluate progressive collapse resistance of structures. ASCE/SEI 7 [3] defines progressive collapse as the spread of an initial local failure from element to element eventually resulting in collapse of an entire structure or a disproportionately large part of it. Following the approaches proposed by Ellinwood and Leyendecker [4], ASCE/SEI 7 [3] defines two general methods for structural design of buildings to mitigate damage due to progressive collapse: indirect and direct design methods. General building codes and standards [3,5] use indirect design by increasing overall integrity of structures. Indirect design is also used in DOD [2]. Although the indirect design method can reduce the risk of progressive collapse [6,7] estimation of post-failure performance of structures designed based on such a method is not readily possible. One approach based on direct design methods to evaluate progressive collapse of structures is to study the effects of instantaneous removal of load-bearing elements, such as columns. GSA [1] and DOD [2] regulations require removal of one load bearing element. These regulations are meant to evaluate general integrity of structures and their capacity of redistributing the loads following severe damage to only one element. While such an approach provides insight as to the extent to which the structures are susceptible to progressive collapse, in reality, the initial damage can affect more than just one column. In this study, using analytical results that are verified against experimental data, the progressive collapse resistance of the Hotel San Diego is evaluated, following the simultaneous explosion (sudden removal) of two adjacent columns, one of which was a corner column. In order to explode the columns, explosives were inserted into predrilled holes in the columns. The columns were then well wrapped with a few layers of protective materials. Therefore, neither air blast nor flying fragments affected the structure.2. Building characteristicsHotel San Diego was constructed in 1914 with a south annex added in 1924. The annex included two separate buildings. Fig. 1 shows a south view of the hotel. Note that in the picture, the first and third stories of the hotel are covered with black fabric. The six story hotel had a non-ductile reinforced concrete (RC) frame structure with hollow clay tile exterior infill walls. The infills in the annex consisted of two withes (layers) of clay tiles with a total thickness of about 8 in (203 mm). The height of the first floor was about 190–800 (6.00 m). The height of other floors and that of the top floor were 100–600 (3.20 m) and 160–1000 (5.13 m), respectively. Fig. 2 shows the second floor of one of the annex buildings. Fig. 3 shows a typical plan of this building, whose response following the simultaneous removal (explosion) of columns A2 and A3 in the first (ground) floor is evaluated in this paper. The floor system consisted of one-way joists running in the longitudinal direction (North–South), as shown in Fig. 3. Based on compression tests of two concrete samples, the average concrete compressive strength was estimated at about 4500 psi (31 MPa) for a standard concrete cylinder. The modulus of elasticity of concrete was estimated at 3820 ksi (26 300 MPa) [5]. Also, based on tension tests of two steel samples having 1/2 in (12.7 mm) square sections, the yield and ultimate tensile strengths were found to be 62 ksi (427 MPa) and 87 ksi (600 MPa), respectively. The steel ultimate tensile strain was measured at 0.17. The modulus of elasticity of steel was set equal to 29 000 ksi (200000 MPa). The building was scheduled to be demolished by implosion. As part of the demolition process, the infill walls were removed from the first and third floors. There was no live load in the building. All nonstructural elements including partitions, plumbing, and furniture were removed prior to implosion. Only beams, columns, joist floor and infill walls on the peripheralbeams were present.3. SensorsConcrete and steel strain gages were used to measure changes in strains of beams and columns. Linear potentiometers were used to measure global and local deformations. The concrete strain gages were 3.5 in (90 mm) long having a maximum strain limit of ±0.02. The steel strain gages could measure up to a strain of ±0.20. The strain gages could operate up to a several hundred kHz sampling rate. The sampling rate used in the experiment was 1000 Hz. Potentiometers were used to capture rotation (integral of curvature over a length) of the beam end regions and global displacement in the building, as described later. The potentiometers had a resolution of about 0.0004 in (0.01 mm) and a maximum operational speed of about 40 in/s (1.0 m/s), while the maximum recorded speed in the experiment was about 14 in/s (0.35m/s).4. Finite element modelUsing the finite element method (FEM), a model of the building was developed in the SAP2000 [8] computer program. The beams and columns are modeled with Bernoulli beam elements. Beams have T or L sections with effective flange width on each side of the web equal to four times the slab thickness [5]. Plastic hinges are assigned to all possible locations where steel bar yielding can occur, including the ends of elements as well as the reinforcing bar cut-off and bend locations. The characteristics of the plastic hinges are obtained using section analyses of the beams and columns and assuming a plastic hinge length equal to half of the section depth. The current version of SAP2000 [8] is not able to track formation of cracks in the elements. In order to find the proper flexural stiffness of sections, an iterative procedure is used as follows. First, the building is analyzed assuming all elements are uncracked. Then, moment demands in the elements are compared with their cracking bending moments, Mcr . The moment of inertia of beam and slab segments are reduced by a coefficient of 0.35 [5], where the demand exceeds the Mcr. The exteriorbeam cracking bending moments under negative and positive moments, are 516 k in (58.2 kN m) and 336 k in (37.9 kN m), respectively. Note that no cracks were formed in the columns. Then the building is reanalyzed and moment diagrams are re-evaluated. This procedure is repeated until all of the cracked regions are properly identified and modeled.The beams in the building did not have top reinforcing bars except at the end regions (see Fig. 4). For instance, no top reinforcement was provided beyond the bend in beam A1–A2, 12 inches away from the face of column A1 (see Figs. 4 and 5). To model the potential loss of flexural strength in those sections, localized crack hinges were assigned at the critical locations where no top rebar was present. Flexural strengths of the hinges were set equal to Mcr. Such sections were assumed to lose their flexural strength when the imposed bending moments reached Mcr.The floor system consisted of joists in the longitudinal direction (North–South). Fig. 6 shows the cross section of a typical floor. In order to account for potential nonlinear response of slabs and joists, floors are molded by beam elements. Joists are modeled with T-sections, having effective flange width on each side of the web equal to four times the slab thickness [5]. Given the large joist spacing between axes 2 and 3, two rectangular beam elements with 20-inch wide sections are used between the joist and the longitudinal beams of axes 2 and 3 to model the slab in the longitudinal direction. To model the behavior of the slab in the transverse direction, equally spaced parallel beams with 20-inch wide rectangular sections are used. There is a difference between the shear flow in the slab and that in the beam elements with rectangular sections modeling the slab. Because of this, the torsional stiffness is setequal to one-half of that of the gross sections [9].The building had infill walls on 2nd, 4th, 5th and 6th floors on the spandrel beamswith some openings (i.e. windows and doors). As mentioned before and as part of the demolition procedure, the infill walls in the 1st and 3rd floors were removed before the test. The infill walls were made of hollow clay tiles, which were in good condition. The net area of the clay tiles was about 1/2 of the gross area. The in-plane action of the infill walls contributes to the building stiffness and strength and affects the building response. Ignoring the effects of the infill walls and excluding them in the model would result in underestimating the building stiffness and strength.Using the SAP2000 computer program [8], two types of modeling for the infills are considered in this study: one uses two dimensional shell elements (Model A) and the other uses compressive struts (Model B) as suggested in FEMA356 [10] guidelines.4.1. Model A (infills modeled by shell elements)Infill walls are modeled with shell elements. However, the current version of the SAP2000 computer program includes only linear shell elements and cannot account for cracking. The tensile strength of the infill walls is set equal to 26 psi, with a modulus of elasticity of 644 ksi [10]. Because the formation ofcracks has a significant effect on the stiffness of the infill walls, the following iterative procedure is used to account for crack formation:(1) Assuming the infill walls are linear and uncracked, a nonlinear time history analysis is run. Note that plastic hinges exist in the beam elements and the segments of the beam elements where moment demand exceeds the cracking moment have a reduced moment of inertia.(2) The cracking pattern in the infill wall is determined by comparing stresses in the shells developed during the analysis with the tensile strength of infills.(3) Nodes are separated at the locations where tensile stress exceeds tensile strength. These steps are continued until the crack regions are properly modeled.4.2. Model B (infills modeled by struts)Infill walls are replaced with compressive struts as described in FEMA 356 [10] guidelines. Orientations of the struts are determined from the deformed shape of the structure after column removal and the location of openings.4.3. Column removalRemoval of the columns is simulated with the following procedure.(1) The structure is analyzed under the permanent loads and the internal forces are determined at the ends of the columns, which will be removed.(2) The model is modified by removing columns A2 and A3 on the first floor. Again the structure is statically analyzed under permanent loads. In this case, the internal forces at the ends of removed columns found in the first step are applied externally to the structure along with permanent loads. Note that the results of this analysis are identical to those of step 1.(3) The equal and opposite column end forces that were applied in the second step are dynamically imposed on the ends of the removed column within one millisecond [11] to simulate the removal of the columns, and dynamic analysis is conducted.4.4. Comparison of analytical and experimental resultsThe maximum calculated vertical displacement of the building occurs at joint A3 inthe second floor. Fig. 7 shows the experimental and analytical (Model A) vertical displacements of this joint (the AEM results will be discussed in the next section). Experimental data is obtained using the recordings of three potentiometers attached to joint A3 on one of their ends, and to the ground on the other ends. The peak displacements obtained experimentally and analytically (Model A) are 0.242 in (6.1 mm) and 0.252 in (6.4 mm), respectively, which differ only by about 4%. The experimental and analytical times corresponding to peak displacement are 0.069 s and 0.066 s, respectively. The analytical results show a permanent displacement of about 0.208 in (5.3 mm), which is about 14% smaller than the corresponding experimental value of 0.242 in (6.1 mm).Fig. 8 compares vertical displacement histories of joint A3 in the second floor estimated analytically based on Models A and B. As can be seen, modeling infills with struts (Model B) results in a maximum vertical displacement of joint A3 equal to about 0.45 in (11.4 mm), which is approximately 80% larger than the value obtained from Model A. Note that the results obtained from Model A are in close agreement with experimental results (see Fig. 7), while Model B significantly overestimates the deformation of the structure. If the maximum vertical displacement were larger, the infill walls were more severely cracked and the struts were more completely formed, the difference between the results of the two models (Models A and B) would be smaller.Fig. 9 compares the experimental and analytical (Model A) displacement of joint A2 in the second floor. Again, while the first peak vertical displacement obtained experimentally and analytically are in good agreement, the analytical permanent displacement under estimates the experimental value.Analytically estimated deformed shapes of the structure at the maximum vertical displacement based on Model A are shown in Fig. 10 with a magnification factor of 200. The experimentally measured deformed shape over the end regions of beamsA1–A2 and A3–B3 in the second floorare represented in the figure by solid lines. A total of 14 potentiometers were located at the top and bottom of the end regions of the second floor beams A1–A2 and A3–B3, which were the most critical elements in load redistribution. The beam top and corresponding bottom potentiometer recordings were used to calculate rotation between the sections where the potentiometer ends were connected. This was done by first finding the difference between the recorded deformations at the top and bottom of the beam, and then dividing the value by the distance (along the height of the beam section) between the two potentiometers. The expected deformed shapes between the measured end regions of the second floor beams are shown by dashed lines. As can be seen in the figures, analytically estimated deformed shapes of the beams are in good agreement with experimentally obtained deformed shapes.Analytical results of Model A show that only two plastic hinges are formed indicating rebar yielding. Also, four sections that did not have negative (top) reinforcement, reached cracking moment capacities and therefore cracked. Fig. 10 shows the locations of all the formed plastic hinges and cracks.。
土木工程专业毕业设计外文翻译
High-Rise BuildingsIn troducti onIt is difficult to defi ne a high-rise buildi ng . One may say that a low-rise build ing ranges from 1 to 2 stories . A medium-rise buildi ng p robably ran ges betwee n 3 or 4 stories up to 10or 20 stories or more .Although the basic principles of vertical and horiz on tal subsystem desig n rema in the samefor low- , medium- , or high-rise build ings , whe n a build ing gets high the verticalsubsystemsbecome a con trolli ng p roblem for two reas ons . Higher vertical loads will requirelarger colu mns , walls , and shafts . But , more sig nifica ntly , the overtur ning mome nt and theshear deflect ions p roduced by lateral forces are much larger and must be carefully pro vided for .The vertical subsystems in a high-rise buildi ng tran smit accumulated gravity load from storyto story , thus requiri ng larger colu mn or wall secti ons to support such loadi ng .In additi onthese same vertical subsystems must tran smit lateral loads , such as wi nd or seismic loads , tothe foun datio ns. However , in con trast to vertical load , lateral load effects on build ings arenot lin ear and in crease rap idly with in crease in height . For example under wind load , theoverturning moment at the base of buildings varies approximately as the square of a buildings mayvary as the fourth power of buildings height , other things being equal. Earthquake produces an evenmore pronoun ced effect.When the structure for a low-or medium-rise building is designed for dead and live load , it isalmost an in here nt property that the colu mns , walls , and stair or elevator shafts can carrymost of the horiz on tal forces . The p roblem is p rimarily one of shear resista nee . Moderateadditi on braci ng for rigid frames in easily be pro vided by filli ng certa in pan els ( or eve n“short ” buildi all pan els ) without in creas ing the sizes of the colu mns and girders otherwise required forvertical loads.Unfortunately , this is not is for high-rise buildings because the problem is p rimarily resistanee to mome nt and deflect ion rather tha n shear alone . Sp ecial structural arra ngeme nts will often have to be made and additi onal structural material is always required for the columns , girders ,walls , and slabs in order to made a high-rise buildi ngs sufficie ntly resista nt to much higherlateral deformati ons .As p reviously men ti oned , the qua ntity of structural material required per square foot offloor of a high-rise buildings is in excess of that required for low-rise buildings . The verticalcomponents carrying the gravity load , such as walls , columns , and shafts , will need to bestrengthened over the full height of the build ings . But qua ntity of material required for resisting lateral forces is eve n more sig nifica nt .With rei nforced con crete , the qua ntity of material also in creases as the nu mber ofstories in creases . But here it should be no ted that the in crease in the weight of material addedfor gravity load is much more sizable tha n steel , whereas for windIn crease the effective width of the mome nt-resisti ng subsystems . This is very usefulbecause in creas ing the width will cut dow n the overtur n force directly and willreduce deflecti on by the third po wer of the width in crease , other things rema iningcin sta nt . However , this does require that vertical components of the widenedsubsystem be suitably connected to actually gain this ben efit.Desig n subsystemssuch that the components are made to in teract in the most efficientmanner . For example , use truss systems with chords and diagonals efficiently stressed ,place reinforcing for walls at critical locati ons , and op timize stiff ness ratios for rigid frames .In crease the material in the most effective resist ing components . For exa mple ,materials added in the lower floors to the flan ges of colu mns and conn ect ing girderswill directly decrease the overall deflect ion and in crease the mome nt resista neewithout con tribut ing mass in the upper floors where the earthquake p roblem isaggravated .Arrange to have the greater part of vertical loads be carried directly on the primarymoment-resisting components . This will help stabilize the build ings aga inst ten sileovertu rning forces by p reco mp ress in gthe major overturn-resisti ng components .The local shear in each story can be best resisted by strategic pl aceme nt if solid wallsor the use of diagonal members in a vertical subsystem . Resist ing these shears solelyby vertical members in bending is usually less econo mical , since achiev ing sufficient bending resista nee in the colu mns and conn ect ing girders will require morematerial and con struct ion en ergy tha n using walls or diago nal members .Sufficie nt horiz on tal dia phragm acti on should be pro vided floor . This will help tobring the various resist ing eleme nts to work together in stead of sep arately .Create mega-frames by joining large vertical and horizontal components such as two or moreelevator shafts at multistory intervals with a heavy floor subsystems , or by use of verydee p girder trusses .Remember that all high-rise build ings are esse ntially vertical can tilevers which aresupported at the ground . When the above principles are judiciously applied , structurally desirable schemes can be obta ined by walls , cores , rigid frames, tubular con struct ion , and othervertical subsystems to achieve horiz on tal stre ngth and rigidity . Some of these app licati ons will now be described in subseque nt secti ons in the followi ng .Shear-Wall SystemsWhen shear walls are comp atible with other fun cti onal requireme nts , they can beeconomically utilized to resist lateral forces in high-rise buildings . For example , ap artme nt build ings n aturally require many sep arati on walls . Whe n some of these are desig ned to be load the in crease for lateral force resista nee is not that much more since the weight of a concrete buildings helps to resist overturn . On the other hand , the problem of desig n for earthquake forces . Additi onal mass in the upper floors will give rise to a greater overall lateral force un der the of seismic effects .In the case of either concrete or steel design , there are certain basic principles for pro vid ing additi onal resista nee to lateral to lateral forces and deflecti ons in high-rise build ings without too much sacrifire in economy .1.2. 3. 4. 5. 6. 7.solid , they can act as shear walls to resist lateral forces and to carry the vertical load aswell . For buildi ngs up to some 20storise , the use of shear walls is com mon .If give n sufficie nt len gth ,such walls can econo mically resist lateral forces up to 30 to 40 stories or more .However , shear walls can resist lateral load only the plane of the walls ( i.e .not in adireti on perpen dicular to them ) . There fore ,it is always n ecessary to pro vide shear walls in two perpen dicular directi ons can be at least in sufficie nt orie ntati on so that lateral force in any direct ion can be resisted .In additi on , that wall layout should reflect con siderati on of any torsi onal effect .In desig n p rogress , two or more shear walls can be conn ected to from L-sha ped or cha nnel-sha ped subsystems .In deed ‘internal shear walls can be conn ected to from a rectangular shaft that will resist lateral forces very efficiently . If all external shear walls are continuously connected , then the whole buildings acts as tube , and conn ected , the n the whole buildi ngs acts as a tube , and is excelle nt Shear-Wall Seystems resist ing lateral loads and torsi on .Whereas con crete shear walls are gen erally of solid type with openings whe n necessary, steel shear walls are usually made of trusses . These trusses can have single diagonals , “X” diagona|sor “ K” arrang e nhs . A trussed wall will have its members act esse ntially in direct tension or comp ressi on un der the acti on of view , and they offer some opportunity anddeflection-limitation point of view , and they offer some opportunity for penetration between members . Of course , the inclined members of trusses must be suitable p laced so as not to in terfere with requireme nts for wion dows and for circulati on service pen etrati ons though these walls .As stated above , the walls of elevator , staircase ,and utility shafts form n atural tubes and are com monly empio yed to resist both vertical and lateral forces . Since these shafts are no rmally recta ngular or circular in cross-sect ion , they can offer an efficie nt means for resist ing mome nts and shear in all directi ons due to tube structural action . But a p roblem in the desig n of these shafts is pro vided sufficie nt stre ngth around door openings and other pen etrati ons through these eleme nts . For rein forced concrete construction , special steel reinforcements are placed around such opening .In steel con struct ion , heavier and more rigid conn ecti ons are required to resist rack ing at the openings .In many high-rise build ings , a comb in ati on of walls and shafts can offer excelle ntresista nee to lateral forces whe n they are suitably located ant conn ected to one ano ther . It is also desirable that the stiff ness offered these subsystems be more-or-less symmertrical in all direct ions .Rigid-Frame SystemsIn the desig n of architectural build ings , rigid-frame systems for resist ing vertical and lateral loads have long bee n acce pted as an imp orta nt and sta ndard means for designingbuilding . They are empioyed for low-and medium means for designing build ings . They are empio yed for low- and medium up to high-rise build ing p erha ps 70 or 100 stories high . Whe n comp ared to shear-wall systems , these rigid frames both with in and at the outside of a buildi ngs . They also make use of the stiff ness in beams and colu mns that are required for the build ings in any case , but the colu mns are made stron ger whe n rigidly conn ected to resist the lateral as well as vertical forces though frame bending .Freque ntly , rigid frames will not be as stiff as shear-wall con struct ion , and therefore may p roduce excessive deflecti ons for the more sle nder high-rise buildi ngs desig ns . But because of this flexibility , they are ofte n con sidered as being more ductile and thus less susceptible to catastr op hic earthquake failure whe n comp ared with ( some ) shear-wall desig ns . For exa mple , if over stress ing occurs at certa in p orti ons of a steel rigid frame ( i.e., near the joi nt ) , ductility will allow the structure as a whole to deflect a little more , but it will by no means colla pse eve n un der a much larger force tha n exp ected on the structure . For this reas on , rigid-frame con struct ion is considered by some to be a “ best ” seisresisting type for high-rise steel buildings . On the other hand ,it is also unlikely that a well-designed share-wall system would colla pse.In the case of con crete rigid frames ,there is a diverge nee of opinion .It true that if a con crete rigid frame is desig ned in the conven ti onal manner , without sp ecial care to produce higher ductility , it will not be able to withstand a catastrophic earthquake that can p roduce forces several times lerger tha n the code desig n earthquake forces . therefore , some believe that it may not have additi onal cap acity p ossessed by steel rigid frames . But moder n research and exp erie nee has in dicated that con crete frames can be desig ned to be ductile , whe n sufficie nt stirr ups and joinery rein forceme nt are designed in to the frame . Modern buildings codes have specifications for the so-called ductile con crete frames . However , at p rese nt , these codesofte n require excessive rein forceme nt at certa in points in the frame so as to cause con gesti on and result in construction difficulties 。
土木工程 专业外语词汇大全中英翻译
土木工程专业外语词汇大全中英翻译1. 综合类大地工程geotechnical engineering1. 综合类反分析法back analysis method1. 综合类基础工程foundation engineering1. 综合类临界状态土力学critical state soil mechanics1. 综合类数值岩土力学numerical geomechanics1. 综合类土soil, earth1. 综合类土动力学soil dynamics1. 综合类土力学soil mechanics1. 综合类岩土工程geotechnical engineering1. 综合类应力路径stress path1. 综合类应力路径法stress path method2. 工程地质及勘察变质岩metamorphic rock2. 工程地质及勘察标准冻深standard frost penetration2. 工程地质及勘察冰川沉积glacial deposit2. 工程地质及勘察冰积层（台）glacial deposit2. 工程地质及勘察残积土eluvial soil, residual soil2. 工程地质及勘察层理beding2. 工程地质及勘察长石feldspar2. 工程地质及勘察沉积岩sedimentary rock2. 工程地质及勘察承压水confined water2. 工程地质及勘察次生矿物secondary mineral2. 工程地质及勘察地质年代geological age2. 工程地质及勘察地质图geological map2. 工程地质及勘察地下水groundwater2. 工程地质及勘察断层fault2. 工程地质及勘察断裂构造fracture structure2. 工程地质及勘察工程地质勘察engineering geological exploration 2. 工程地质及勘察海积层（台）marine deposit2. 工程地质及勘察海相沉积marine deposit2. 工程地质及勘察花岗岩granite2. 工程地质及勘察滑坡landslide2. 工程地质及勘察化石fossil2. 工程地质及勘察化学沉积岩chemical sedimentary rock2. 工程地质及勘察阶地terrace2. 工程地质及勘察节理joint2. 工程地质及勘察解理cleavage2. 工程地质及勘察喀斯特karst2. 工程地质及勘察矿物硬度hardness of minerals2. 工程地质及勘察砾岩conglomerate2. 工程地质及勘察流滑flow slide2. 工程地质及勘察陆相沉积continental sedimentation2. 工程地质及勘察泥石流mud flow, debris flow2. 工程地质及勘察年粘土矿物clay minerals2. 工程地质及勘察凝灰岩tuff2. 工程地质及勘察牛轭湖ox-bow lake2. 工程地质及勘察浅成岩hypabyssal rock2. 工程地质及勘察潜水ground water2. 工程地质及勘察侵入岩intrusive rock2. 工程地质及勘察取土器geotome2. 工程地质及勘察砂岩sandstone2. 工程地质及勘察砂嘴spit, sand spit2. 工程地质及勘察山岩压力rock pressure2. 工程地质及勘察深成岩plutionic rock2. 工程地质及勘察石灰岩limestone2. 工程地质及勘察石英quartz2. 工程地质及勘察松散堆积物rickle2. 工程地质及勘察围限地下水（台）confined ground water 2. 工程地质及勘察泻湖lagoon2. 工程地质及勘察岩爆rock burst2. 工程地质及勘察岩层产状attitude of rock2. 工程地质及勘察岩浆岩magmatic rock, igneous rock2. 工程地质及勘察岩脉dike, dgke2. 工程地质及勘察岩石风化程度degree of rock weathering 2. 工程地质及勘察岩石构造structure of rock2. 工程地质及勘察岩石结构texture of rock2. 工程地质及勘察岩体rock mass2. 工程地质及勘察页岩shale2. 工程地质及勘察原生矿物primary mineral2. 工程地质及勘察云母mica2. 工程地质及勘察造岩矿物rock-forming mineral2. 工程地质及勘察褶皱fold, folding2. 工程地质及勘察钻孔柱状图bore hole columnar section3. 土的分类饱和土saturated soil3. 土的分类超固结土overconsolidated soil3. 土的分类冲填土dredger fill3. 土的分类充重塑土3. 土的分类冻土frozen soil, tjaele3. 土的分类非饱和土unsaturated soil3. 土的分类分散性土dispersive soil3. 土的分类粉土silt, mo3. 土的分类粉质粘土silty clay3. 土的分类高岭石kaolinite3. 土的分类过压密土（台）overconsolidated soil3. 土的分类红粘土red clay, adamic earth3. 土的分类黄土loess, huangtu(China)3. 土的分类蒙脱石montmorillonite3. 土的分类泥炭peat, bog muck3. 土的分类年粘土clay3. 土的分类年粘性土cohesive soil, clayey soil3. 土的分类膨胀土expansive soil, swelling soil3. 土的分类欠固结粘土underconsolidated soil3. 土的分类区域性土zonal soil3. 土的分类人工填土fill, artificial soil3. 土的分类软粘土soft clay, mildclay, mickle3. 土的分类砂土sand3. 土的分类湿陷性黄土collapsible loess, slumping loess3. 土的分类素填土plain fill3. 土的分类塑性图plasticity chart3. 土的分类碎石土stone, break stone, broken stone, channery, chat, crushed stone, deritus 3. 土的分类未压密土（台）underconsolidated clay3. 土的分类无粘性土cohesionless soil, frictional soil, non-cohesive soil3. 土的分类岩石rock3. 土的分类伊利土illite3. 土的分类有机质土organic soil3. 土的分类淤泥muck, gyttja, mire, slush3. 土的分类淤泥质土mucky soil3. 土的分类原状土undisturbed soil3. 土的分类杂填土miscellaneous fill3. 土的分类正常固结土normally consolidated soil3. 土的分类正常压密土（台）normally consolidated soil3. 土的分类自重湿陷性黄土self weight collapse loess4. 土的物理性质阿太堡界限Atterberg limits4. 土的物理性质饱和度degree of saturation4. 土的物理性质饱和密度saturated density4. 土的物理性质饱和重度saturated unit weight4. 土的物理性质比重specific gravity4. 土的物理性质稠度consistency4. 土的物理性质不均匀系数coefficient of uniformity, uniformity coefficient4. 土的物理性质触变thixotropy4. 土的物理性质单粒结构single-grained structure4. 土的物理性质蜂窝结构honeycomb structure4. 土的物理性质干重度dry unit weight4. 土的物理性质干密度dry density4. 土的物理性质塑性指数plasticity index4. 土的物理性质含水量water content, moisture content4. 土的物理性质活性指数4. 土的物理性质级配gradation, grading4. 土的物理性质结合水bound water, combined water, held water4. 土的物理性质界限含水量Atterberg limits4. 土的物理性质颗粒级配particle size distribution of soils, mechanical composition of soil 4. 土的物理性质可塑性plasticity4. 土的物理性质孔隙比void ratio4. 土的物理性质孔隙率porosity4. 土的物理性质粒度granularity, grainness, grainage4. 土的物理性质粒组fraction, size fraction4. 土的物理性质毛细管水capillary water4. 土的物理性质密度density4. 土的物理性质密实度compactionness4. 土的物理性质年粘性土的灵敏度sensitivity of cohesive soil4. 土的物理性质平均粒径mean diameter, average grain diameter4. 土的物理性质曲率系数coefficient of curvature4. 土的物理性质三相图block diagram, skeletal diagram, three phase diagram4. 土的物理性质三相土tri-phase soil4. 土的物理性质湿陷起始应力initial collapse pressure4. 土的物理性质湿陷系数coefficient of collapsibility4. 土的物理性质缩限shrinkage limit4. 土的物理性质土的构造soil texture4. 土的物理性质土的结构soil structure4. 土的物理性质土粒相对密度specific density of solid particles4. 土的物理性质土中气air in soil4. 土的物理性质土中水water in soil4. 土的物理性质团粒aggregate, cumularpharolith4. 土的物理性质限定粒径constrained diameter4. 土的物理性质相对密度relative density, density index4. 土的物理性质相对压密度relative compaction, compacting factor, percent compaction, coefficient of compaction4. 土的物理性质絮状结构flocculent structure4. 土的物理性质压密系数coefficient of consolidation4. 土的物理性质压缩性compressibility4. 土的物理性质液限liquid limit4. 土的物理性质液性指数liquidity index4. 土的物理性质游离水（台）free water4. 土的物理性质有效粒径effective diameter, effective grain size, effective size4. 土的物理性质有效密度effective density4. 土的物理性质有效重度effective unit weight4. 土的物理性质重力密度unit weight4. 土的物理性质自由水free water, gravitational water, groundwater, phreatic water4. 土的物理性质组构fabric4. 土的物理性质最大干密度maximum dry density4. 土的物理性质最优含水量optimum water content5. 渗透性和渗流达西定律Darcy s law5. 渗透性和渗流管涌piping5. 渗透性和渗流浸润线phreatic line5. 渗透性和渗流临界水力梯度critical hydraulic gradient5. 渗透性和渗流流函数flow function5. 渗透性和渗流流土flowing soil5. 渗透性和渗流流网flow net5. 渗透性和渗流砂沸sand boiling5. 渗透性和渗流渗流seepage5. 渗透性和渗流渗流量seepage discharge5. 渗透性和渗流渗流速度seepage velocity5. 渗透性和渗流渗透力seepage force5. 渗透性和渗流渗透破坏seepage failure5. 渗透性和渗流渗透系数coefficient of permeability5. 渗透性和渗流渗透性permeability5. 渗透性和渗流势函数potential function5. 渗透性和渗流水力梯度hydraulic gradient6. 地基应力和变形变形deformation6. 地基应力和变形变形模量modulus of deformation6. 地基应力和变形泊松比Poisson s ratio6. 地基应力和变形布西涅斯克解Boussinnesq s solution6. 地基应力和变形残余变形residual deformation6. 地基应力和变形残余孔隙水压力residual pore water pressure6. 地基应力和变形超静孔隙水压力excess pore water pressure6. 地基应力和变形沉降settlement6. 地基应力和变形沉降比settlement ratio6. 地基应力和变形次固结沉降secondary consolidation settlement6. 地基应力和变形次固结系数coefficient of secondary consolidation6. 地基应力和变形地基沉降的弹性力学公式elastic formula for settlement calculation 6. 地基应力和变形分层总和法layerwise summation method6. 地基应力和变形负孔隙水压力negative pore water pressure6. 地基应力和变形附加应力superimposed stress6. 地基应力和变形割线模量secant modulus6. 地基应力和变形固结沉降consolidation settlement6. 地基应力和变形规范沉降计算法settlement calculation by specification6. 地基应力和变形回弹变形rebound deformation6. 地基应力和变形回弹模量modulus of resilience6. 地基应力和变形回弹系数coefficient of resilience6. 地基应力和变形回弹指数swelling index6. 地基应力和变形建筑物的地基变形允许值allowable settlement of building6. 地基应力和变形剪胀dilatation6. 地基应力和变形角点法corner-points method6. 地基应力和变形孔隙气压力pore air pressure6. 地基应力和变形孔隙水压力pore water pressure6. 地基应力和变形孔隙压力系数Apore pressure parameter A6. 地基应力和变形孔隙压力系数Bpore pressure parameter B6. 地基应力和变形明德林解Mindlin s solution6. 地基应力和变形纽马克感应图Newmark chart6. 地基应力和变形切线模量tangent modulus6. 地基应力和变形蠕变creep6. 地基应力和变形三向变形条件下的固结沉降three-dimensional consolidation settlement 6. 地基应力和变形瞬时沉降immediate settlement6. 地基应力和变形塑性变形plastic deformation6. 地基应力和变形谈弹性变形elastic deformation6. 地基应力和变形谈弹性模量elastic modulus6. 地基应力和变形谈弹性平衡状态state of elastic equilibrium6. 地基应力和变形体积变形模量volumetric deformation modulus6. 地基应力和变形先期固结压力preconsolidation pressure6. 地基应力和变形压缩层6. 地基应力和变形压缩模量modulus of compressibility6. 地基应力和变形压缩系数coefficient of compressibility6. 地基应力和变形压缩性compressibility6. 地基应力和变形压缩指数compression index6. 地基应力和变形有效应力effective stress6. 地基应力和变形自重应力self-weight stress6. 地基应力和变形总应力total stress approach of shear strength6. 地基应力和变形最终沉降final settlement7. 固结巴隆固结理论Barron s consolidation theory7. 固结比奥固结理论Biot s consolidation theory7. 固结超固结比over-consolidation ratio7. 固结超静孔隙水压力excess pore water pressure7. 固结次固结secondary consolidation7. 固结次压缩（台）secondary consolidatin7. 固结单向度压密（台）one-dimensional consolidation7. 固结多维固结multi-dimensional consolidation7. 固结固结consolidation7. 固结固结度degree of consolidation7. 固结固结理论theory of consolidation7. 固结固结曲线consolidation curve7. 固结固结速率rate of consolidation7. 固结固结系数coefficient of consolidation7. 固结固结压力consolidation pressure7. 固结回弹曲线rebound curve7. 固结井径比drain spacing ratio7. 固结井阻well resistance7. 固结曼代尔－克雷尔效应Mandel-Cryer effect7. 固结潜变（台）creep7. 固结砂井sand drain7. 固结砂井地基平均固结度average degree of consolidation of sand-drained ground7. 固结时间对数拟合法logrithm of time fitting method7. 固结时间因子time factor7. 固结太沙基固结理论Terzaghi s consolidation theory7. 固结太沙基－伦杜列克扩散方程Terzaghi-Rendulic diffusion equation7. 固结先期固结压力preconsolidation pressure7. 固结压密（台）consolidation7. 固结压密度（台）degree of consolidation7. 固结压缩曲线cpmpression curve7. 固结一维固结one dimensional consolidation7. 固结有效应力原理principle of effective stress7. 固结预压密压力（台）preconsolidation pressure7. 固结原始压缩曲线virgin compression curve7. 固结再压缩曲线recompression curve7. 固结主固结primary consolidation7. 固结主压密（台）primary consolidation7. 固结准固结压力pseudo-consolidation pressure7. 固结K0固结consolidation under K0 condition8. 抗剪强度安息角（台）angle of repose8. 抗剪强度不排水抗剪强度undrained shear strength8. 抗剪强度残余内摩擦角residual angle of internal friction8. 抗剪强度残余强度residual strength8. 抗剪强度长期强度long-term strength8. 抗剪强度单轴抗拉强度uniaxial tension test8. 抗剪强度动强度dynamic strength of soils8. 抗剪强度峰值强度peak strength8. 抗剪强度伏斯列夫参数Hvorslev parameter8. 抗剪强度剪切应变速率shear strain rate8. 抗剪强度抗剪强度shear strength8. 抗剪强度抗剪强度参数shear strength parameter8. 抗剪强度抗剪强度有效应力法effective stress approach of shear strength 8. 抗剪强度抗剪强度总应力法total stress approach of shear strength8. 抗剪强度库仑方程Coulomb s equation8. 抗剪强度摩尔包线Mohr s envelope8. 抗剪强度摩尔－库仑理论Mohr-Coulomb theory8. 抗剪强度内摩擦角angle of internal friction8. 抗剪强度年粘聚力cohesion8. 抗剪强度破裂角angle of rupture8. 抗剪强度破坏准则failure criterion8. 抗剪强度十字板抗剪强度vane strength8. 抗剪强度无侧限抗压强度unconfined compression strength8. 抗剪强度有效内摩擦角effective angle of internal friction8. 抗剪强度有效粘聚力effective cohesion intercept8. 抗剪强度有效应力破坏包线effective stress failure envelope8. 抗剪强度有效应力强度参数effective stress strength parameter8. 抗剪强度有效应力原理principle of effective stress8. 抗剪强度真内摩擦角true angle internal friction8. 抗剪强度真粘聚力true cohesion8. 抗剪强度总应力破坏包线total stress failure envelope8. 抗剪强度总应力强度参数total stress strength parameter9. 本构模型本构模型constitutive model9. 本构模型边界面模型boundary surface model9. 本构模型层向各向同性体模型cross anisotropic model9. 本构模型超弹性模型hyperelastic model9. 本构模型德鲁克－普拉格准则Drucker-Prager criterion9. 本构模型邓肯－张模型Duncan-Chang model9. 本构模型动剪切强度9. 本构模型非线性弹性模量nonlinear elastic model9. 本构模型盖帽模型cap model9. 本构模型刚塑性模型rigid plastic model9. 本构模型割线模量secant modulus9. 本构模型广义冯·米赛斯屈服准则extended von Mises yield criterion 9. 本构模型广义特雷斯卡屈服准则extended tresca yield criterion9. 本构模型加工软化work softening9. 本构模型加工硬化work hardening9. 本构模型加工硬化定律strain harding law9. 本构模型剑桥模型Cambridge model9. 本构模型柯西弹性模型Cauchy elastic model9. 本构模型拉特－邓肯模型Lade-Duncan model9. 本构模型拉特屈服准则Lade yield criterion9. 本构模型理想弹塑性模型ideal elastoplastic model9. 本构模型临界状态弹塑性模型critical state elastoplastic model9. 本构模型流变学模型rheological model9. 本构模型流动规则flow rule9. 本构模型摩尔－库仑屈服准则Mohr-Coulomb yield criterion9. 本构模型内蕴时间塑性模型endochronic plastic model9. 本构模型内蕴时间塑性理论endochronic theory9. 本构模型年粘弹性模型viscoelastic model9. 本构模型切线模量tangent modulus9. 本构模型清华弹塑性模型Tsinghua elastoplastic model9. 本构模型屈服面yield surface9. 本构模型沈珠江三重屈服面模型Shen Zhujiang three yield surface method 9. 本构模型双参数地基模型9. 本构模型双剪应力屈服模型twin shear stress yield criterion9. 本构模型双曲线模型hyperbolic model9. 本构模型松岗元－中井屈服准则Matsuoka-Nakai yield criterion9. 本构模型塑性形变理论9. 本构模型谈弹塑性模量矩阵elastoplastic modulus matrix9. 本构模型谈弹塑性模型elastoplastic modulus9. 本构模型谈弹塑性增量理论incremental elastoplastic theory9. 本构模型谈弹性半空间地基模型elastic half-space foundation model9. 本构模型谈弹性变形elastic deformation9. 本构模型谈弹性模量elastic modulus9. 本构模型谈弹性模型elastic model9. 本构模型魏汝龙－Khosla－Wu模型Wei Rulong-Khosla-Wu model9. 本构模型文克尔地基模型Winkler foundation model9. 本构模型修正剑桥模型modified cambridge model9. 本构模型准弹性模型hypoelastic model10. 地基承载力冲剪破坏punching shear failure10. 地基承载力次层（台）substratum10. 地基承载力地基subgrade, ground, foundation soil10. 地基承载力地基承载力bearing capacity of foundation soil10. 地基承载力地基极限承载力ultimate bearing capacity of foundation soil10. 地基承载力地基允许承载力allowable bearing capacity of foundation soil10. 地基承载力地基稳定性stability of foundation soil10. 地基承载力汉森地基承载力公式Hansen s ultimate bearing capacity formula10. 地基承载力极限平衡状态state of limit equilibrium10. 地基承载力加州承载比（美国）California Bearing Ratio10. 地基承载力局部剪切破坏local shear failure10. 地基承载力临塑荷载critical edge pressure10. 地基承载力梅耶霍夫极限承载力公式Meyerhof s ultimate bearing capacity formula 10. 地基承载力普朗特承载力理论Prandel bearing capacity theory10. 地基承载力斯肯普顿极限承载力公式Skempton s ultimate bearing capacity formula 10. 地基承载力太沙基承载力理论Terzaghi bearing capacity theory10. 地基承载力魏锡克极限承载力公式V esic s ultimate bearing capacity formula10. 地基承载力整体剪切破坏general shear failure11. 土压力被动土压力passive earth pressure11. 土压力被动土压力系数coefficient of passive earth pressure11. 土压力极限平衡状态state of limit equilibrium11. 土压力静止土压力earth pressue at rest11. 土压力静止土压力系数coefficient of earth pressur at rest11. 土压力库仑土压力理论Coulomb s earth pressure theory11. 土压力库尔曼图解法Culmannn construction11. 土压力朗肯土压力理论Rankine s earth pressure theory11. 土压力朗肯状态Rankine state11. 土压力谈弹性平衡状态state of elastic equilibrium11. 土压力土压力earth pressure11. 土压力主动土压力active earth pressure11. 土压力主动土压力系数coefficient of active earth pressure12. 土坡稳定分析安息角（台）angle of repose12. 土坡稳定分析毕肖普法Bishop method12. 土坡稳定分析边坡稳定安全系数safety factor of slope12. 土坡稳定分析不平衡推理传递法unbalanced thrust transmission method12. 土坡稳定分析费伦纽斯条分法Fellenius method of slices12. 土坡稳定分析库尔曼法Culmann method12. 土坡稳定分析摩擦圆法friction circle method12. 土坡稳定分析摩根斯坦－普拉斯法Morgenstern-Price method12. 土坡稳定分析铅直边坡的临界高度critical height of vertical slope12. 土坡稳定分析瑞典圆弧滑动法Swedish circle method12. 土坡稳定分析斯宾赛法Spencer method12. 土坡稳定分析泰勒法Taylor method12. 土坡稳定分析条分法slice method12. 土坡稳定分析土坡slope12. 土坡稳定分析土坡稳定分析slope stability analysis12. 土坡稳定分析土坡稳定极限分析法limit analysis method of slope stability 12. 土坡稳定分析土坡稳定极限平衡法limit equilibrium method of slope stability 12. 土坡稳定分析休止角angle of repose12. 土坡稳定分析扬布普遍条分法Janbu general slice method12. 土坡稳定分析圆弧分析法circular arc analysis13. 土的动力性质比阻尼容量specific gravity capacity13. 土的动力性质波的弥散特性dispersion of waves13. 土的动力性质波速法wave velocity method13. 土的动力性质材料阻尼material damping13. 土的动力性质初始液化initial liquefaction13. 土的动力性质地基固有周期natural period of soil site13. 土的动力性质动剪切模量dynamic shear modulus of soils13. 土的动力性质动力布西涅斯克解dynamic solution of Boussinesq13. 土的动力性质动力放大因素dynamic magnification factor13. 土的动力性质动力性质dynamic properties of soils13. 土的动力性质动强度dynamic strength of soils13. 土的动力性质骨架波akeleton waves in soils13. 土的动力性质几何阻尼geometric damping13. 土的动力性质抗液化强度liquefaction stress13. 土的动力性质孔隙流体波fluid wave in soil13. 土的动力性质损耗角loss angle13. 土的动力性质往返活动性reciprocating activity13. 土的动力性质无量纲频率dimensionless frequency13. 土的动力性质液化liquefaction13. 土的动力性质液化势评价evaluation of liquefaction potential13. 土的动力性质液化应力比stress ratio of liquefaction13. 土的动力性质应力波stress waves in soils13. 土的动力性质振陷dynamic settlement13. 土的动力性质阻尼damping of soil13. 土的动力性质阻尼比damping ratio14. 挡土墙挡土墙retaining wall14. 挡土墙挡土墙排水设施14. 挡土墙挡土墙稳定性stability of retaining wall14. 挡土墙垛式挡土墙14. 挡土墙扶垛式挡土墙counterfort retaining wall14. 挡土墙后垛墙（台）counterfort retaining wall14. 挡土墙基础墙foundation wall14. 挡土墙加筋土挡墙reinforced earth bulkhead14. 挡土墙锚定板挡土墙anchored plate retaining wall14. 挡土墙锚定式板桩墙anchored sheet pile wall14. 挡土墙锚杆式挡土墙anchor rod retaining wall14. 挡土墙悬壁式板桩墙cantilever sheet pile wall14. 挡土墙悬壁式挡土墙cantilever sheet pile wall14. 挡土墙重力式挡土墙gravity retaining wall15. 板桩结构物板桩sheet pile15. 板桩结构物板桩结构sheet pile structure15. 板桩结构物钢板桩steel sheet pile15. 板桩结构物钢筋混凝土板桩reinforced concrete sheet pile15. 板桩结构物钢桩steel pile15. 板桩结构物灌注桩cast-in-place pile15. 板桩结构物拉杆tie rod15. 板桩结构物锚定式板桩墙anchored sheet pile wall15. 板桩结构物锚固技术anchoring15. 板桩结构物锚座Anchorage15. 板桩结构物木板桩wooden sheet pile15. 板桩结构物木桩timber piles15. 板桩结构物悬壁式板桩墙cantilever sheet pile wall16. 基坑开挖与降水板桩围护sheet pile-braced cuts16. 基坑开挖与降水电渗法electro-osmotic drainage16. 基坑开挖与降水管涌piping16. 基坑开挖与降水基底隆起heave of base16. 基坑开挖与降水基坑降水dewatering16. 基坑开挖与降水基坑失稳instability (failure) of foundation pit16. 基坑开挖与降水基坑围护bracing of foundation pit16. 基坑开挖与降水减压井relief well16. 基坑开挖与降水降低地下水位法dewatering method16. 基坑开挖与降水井点系统well point system16. 基坑开挖与降水喷射井点eductor well point16. 基坑开挖与降水铅直边坡的临界高度critical height of vertical slope 16. 基坑开挖与降水砂沸sand boiling16. 基坑开挖与降水深井点deep well point16. 基坑开挖与降水真空井点vacuum well point16. 基坑开挖与降水支撑围护braced cuts17. 浅基础杯形基础17. 浅基础补偿性基础compensated foundation17. 浅基础持力层bearing stratum17. 浅基础次层（台）substratum17. 浅基础单独基础individual footing17. 浅基础倒梁法inverted beam method17. 浅基础刚性角pressure distribution angle of masonary foundation 17. 浅基础刚性基础rigid foundation17. 浅基础高杯口基础17. 浅基础基础埋置深度embeded depth of foundation17. 浅基础基床系数coefficient of subgrade reaction17. 浅基础基底附加应力net foundation pressure17. 浅基础交叉条形基础cross strip footing17. 浅基础接触压力contact pressure17. 浅基础静定分析法（浅基础）static analysis (shallow foundation)17. 浅基础壳体基础shell foundation17. 浅基础扩展基础spread footing17. 浅基础片筏基础mat foundation17. 浅基础浅基础shallow foundation17. 浅基础墙下条形基础17. 浅基础热摩奇金法Zemochkin s method17. 浅基础柔性基础flexible foundation17. 浅基础上部结构－基础－土共同作用分析structure- foundation-soil interactionanalysis 17. 浅基础谈弹性地基梁（板）分析analysis of beams and slabs on elastic foundation 17. 浅基础条形基础strip footing17. 浅基础下卧层substratum17. 浅基础箱形基础box foundation17. 浅基础柱下条形基础18. 深基础贝诺托灌注桩Benoto cast-in-place pile18. 深基础波动方程分析Wave equation analysis18. 深基础场铸桩（台)cast-in-place pile18. 深基础沉管灌注桩diving casting cast-in-place pile18. 深基础沉井基础open-end caisson foundation18. 深基础沉箱基础box caisson foundation18. 深基础成孔灌注同步桩synchronous pile18. 深基础承台pile caps18. 深基础充盈系数fullness coefficient18. 深基础单桩承载力bearing capacity of single pile18. 深基础单桩横向极限承载力ultimate lateral resistance of single pile18. 深基础单桩竖向抗拔极限承载力vertical ultimate uplift resistance of single pile18. 深基础单桩竖向抗压容许承载力vertical ultimate carrying capacity of single pile18. 深基础单桩竖向抗压极限承载力vertical allowable load capacity of single pile18. 深基础低桩承台low pile cap18. 深基础地下连续墙diaphgram wall18. 深基础点承桩（台）end-bearing pile18. 深基础动力打桩公式dynamic pile driving formula18. 深基础端承桩end-bearing pile18. 深基础法兰基灌注桩Franki pile18. 深基础负摩擦力negative skin friction of pile18. 深基础钢筋混凝土预制桩precast reinforced concrete piles18. 深基础钢桩steel pile18. 深基础高桩承台high-rise pile cap18. 深基础灌注桩cast-in-place pile18. 深基础横向载荷桩laterally loaded vertical piles18. 深基础护壁泥浆slurry coat method18. 深基础回转钻孔灌注桩rotatory boring cast-in-place pile18. 深基础机挖异形灌注桩18. 深基础静力压桩silent piling18. 深基础抗拔桩uplift pile18. 深基础抗滑桩anti-slide pile18. 深基础摩擦桩friction pile18. 深基础木桩timber piles18. 深基础嵌岩灌注桩piles set into rock18. 深基础群桩pile groups18. 深基础群桩效率系数efficiency factor of pile groups18. 深基础群桩效应efficiency of pile groups18. 深基础群桩竖向极限承载力vertical ultimate load capacity of pile groups 18. 深基础深基础deep foundation18. 深基础竖直群桩横向极限承载力18. 深基础无桩靴夯扩灌注桩rammed bulb ile18. 深基础旋转挤压灌注桩18. 深基础桩piles18. 深基础桩基动测技术dynamic pile test18. 深基础钻孔墩基础drilled-pier foundation18. 深基础钻孔扩底灌注桩under-reamed bored pile18. 深基础钻孔压注桩starsol enbesol pile18. 深基础最后贯入度final set19. 地基处理表层压密法surface compaction19. 地基处理超载预压surcharge preloading19. 地基处理袋装砂井sand wick19. 地基处理地工织物geofabric, geotextile19. 地基处理地基处理ground treatment, foundation treatment19. 地基处理电动化学灌浆electrochemical grouting19. 地基处理电渗法electro-osmotic drainage19. 地基处理顶升纠偏法19. 地基处理定喷directional jet grouting19. 地基处理冻土地基处理frozen foundation improvement19. 地基处理短桩处理treatment with short pile19. 地基处理堆载预压法preloading19. 地基处理粉体喷射深层搅拌法powder deep mixing method19. 地基处理复合地基composite foundation19. 地基处理干振成孔灌注桩vibratory bored pile19. 地基处理高压喷射注浆法jet grounting19. 地基处理灌浆材料injection material19. 地基处理灌浆法grouting19. 地基处理硅化法silicification19. 地基处理夯实桩compacting pile19. 地基处理化学灌浆chemical grouting19. 地基处理换填法cushion19. 地基处理灰土桩lime soil pile19. 地基处理基础加压纠偏法19. 地基处理挤密灌浆compaction grouting19. 地基处理挤密桩compaction pile, compacted column19. 地基处理挤淤法displacement method19. 地基处理加筋法reinforcement method19. 地基处理加筋土reinforced earth19. 地基处理碱液法soda solution grouting19. 地基处理浆液深层搅拌法grout deep mixing method19. 地基处理降低地下水位法dewatering method19. 地基处理纠偏技术19. 地基处理坑式托换pit underpinning19. 地基处理冷热处理法freezing and heating19. 地基处理锚固技术anchoring19. 地基处理锚杆静压桩托换anchor pile underpinning19. 地基处理排水固结法consolidation19. 地基处理膨胀土地基处理expansive foundation treatment19. 地基处理劈裂灌浆fracture grouting19. 地基处理浅层处理shallow treatment19. 地基处理强夯法dynamic compaction19. 地基处理人工地基artificial foundation19. 地基处理容许灌浆压力allowable grouting pressure19. 地基处理褥垫pillow19. 地基处理软土地基soft clay ground19. 地基处理砂井sand drain19. 地基处理砂井地基平均固结度average degree of consolidation of sand-drained ground 19. 地基处理砂桩sand column19. 地基处理山区地基处理foundation treatment in mountain area19. 地基处理深层搅拌法deep mixing method19. 地基处理渗入性灌浆seep-in grouting19. 地基处理湿陷性黄土地基处理collapsible loess treatment19. 地基处理石灰系深层搅拌法lime deep mixing method19. 地基处理石灰桩lime column, limepile19. 地基处理树根桩root pile19. 地基处理水泥土水泥掺合比cement mixing ratio19. 地基处理水泥系深层搅拌法cement deep mixing method19. 地基处理水平旋喷horizontal jet grouting19. 地基处理塑料排水带plastic drain19. 地基处理碎石桩gravel pile, stone pillar19. 地基处理掏土纠偏法19. 地基处理天然地基natural foundation19. 地基处理土工聚合物Geopolymer19. 地基处理土工织物geofabric, geotextile19. 地基处理土桩earth pile19. 地基处理托换技术underpinning technique19. 地基处理外掺剂additive19. 地基处理旋喷jet grouting19. 地基处理药液灌浆chemical grouting19. 地基处理预浸水法presoaking19. 地基处理预压法preloading19. 地基处理真空预压vacuum preloading19. 地基处理振冲法vibroflotation method19. 地基处理振冲密实法vibro-compaction19. 地基处理振冲碎石桩vibro replacement stone column19. 地基处理振冲置换法vibro-replacement19. 地基处理振密、挤密法vibro-densification, compacting19. 地基处理置换率（复合地基）replacement ratio19. 地基处理重锤夯实法tamping19. 地基处理桩式托换pile underpinning19. 地基处理桩土应力比stress ratio20. 动力机器基础比阻尼容量specific gravity capacity20. 动力机器基础等效集总参数法constant strain rate consolidation test20. 动力机器基础地基固有周期natural period of soil site20. 动力机器基础动基床反力法dynamic subgrade reaction method20. 动力机器基础动力放大因素dynamic magnification factor20. 动力机器基础隔振isolation20. 动力机器基础基础振动foundation vibration20. 动力机器基础基础振动半空间理论elastic half-space theory of foundation vibr ation20. 动力机器基础基础振动容许振幅allowable amplitude of foundation vibration 20. 动力机器基础基础自振频率natural frequency of foundation20. 动力机器基础集总参数法lumped parameter method20. 动力机器基础吸收系数absorption coefficient20. 动力机器基础质量－弹簧－阻尼器系统mass-spring-dushpot system21. 地基基础抗震地基固有周期natural period of soil site21. 地基基础抗震地震earthquake, seism, temblor21. 地基基础抗震地震持续时间duration of earthquake21. 地基基础抗震地震等效均匀剪应力equivalent even shear stress of earthquake 21. 地基基础抗震地震反应谱earthquake response spectrum21. 地基基础抗震地震烈度earthquake intensity21. 地基基础抗震地震震级earthquake magnitude21. 地基基础抗震地震卓越周期seismic predominant period21. 地基基础抗震地震最大加速度maximum acceleration of earthquake21. 地基基础抗震动力放大因数dynamic magnification factor21. 地基基础抗震对数递减率logrithmic decrement21. 地基基础抗震刚性系数coefficient of rigidity21. 地基基础抗震吸收系数absorption coefficient22. 室内土工试验比重试验specific gravity test22. 室内土工试验变水头渗透试验falling head permeability test22. 室内土工试验不固结不排水试验unconsolidated-undrained triaxial test22. 室内土工试验常规固结试验routine consolidation test22. 室内土工试验常水头渗透试验constant head permeability test22. 室内土工试验单剪仪simple shear apparatus22. 室内土工试验单轴拉伸试验uniaxial tensile test22. 室内土工试验等速加荷固结试验constant loading rate consolidatin test22. 室内土工试验等梯度固结试验constant gradient consolidation test22. 室内土工试验等应变速率固结试验equivalent lumped parameter method22. 室内土工试验反复直剪强度试验repeated direct shear test22. 室内土工试验反压饱和法back pressure saturation method22. 室内土工试验高压固结试验high pressure consolidation test22. 室内土工试验各向不等压固结不排水试验consoidated anisotropically undrained test 22. 室内土工试验各向不等压固结排水试验consolidated anisotropically drained test 22. 室内土工试验共振柱试验resonant column test22. 室内土工试验固结不排水试验consolidated undrained triaxial test22. 室内土工试验固结快剪试验consolidated quick direct shear test22. 室内土工试验固结排水试验consolidated drained triaxial test22. 室内土工试验固结试验consolidation test22. 室内土工试验含水量试验water content test22. 室内土工试验环剪试验ring shear test22. 室内土工试验黄土湿陷试验loess collapsibility test22. 室内土工试验击实试验22. 室内土工试验界限含水量试验Atterberg limits test22. 室内土工试验卡萨格兰德法Casagrande s method22. 室内土工试验颗粒分析试验grain size analysis test22. 室内土工试验孔隙水压力消散试验pore pressure dissipation test22. 室内土工试验快剪试验quick direct shear test22. 室内土工试验快速固结试验fast consolidation test22. 室内土工试验离心模型试验centrifugal model test22. 室内土工试验连续加荷固结试验continual loading test22. 室内土工试验慢剪试验consolidated drained direct shear test22. 室内土工试验毛细管上升高度试验capillary rise test22. 室内土工试验密度试验density test22. 室内土工试验扭剪仪torsion shear apparatus22. 室内土工试验膨胀率试验swelling rate test22. 室内土工试验平面应变仪plane strain apparatus22. 室内土工试验三轴伸长试验triaxial extension test22. 室内土工试验三轴压缩试验triaxial compression test22. 室内土工试验砂的相对密实度试验sand relative density test22. 室内土工试验筛分析sieve analysis。
土木工程外文翻译-原文
外文原文Response of a reinforced concrete infilled—frame structure to removal of twoadjacent columnsMehrdad Sasani_Northeastern University, 400 Snell Engineering Center，Boston，MA 02115, UnitedStatesReceived 27 June 2007；received in revised form 26 December 2007；accepted 24January 2008Available online 19 March 2008AbstractThe response of Hotel San Diego，a six—story reinforced concrete infilled-frame structure，is evaluated following the simultaneous removal of two adjacent exterior columns. Analytical models of the structure using the Finite Element Method as well as the Applied Element Method are used to calculate global and local deformations. The analytical results show good agreement with experimental data. The structure resisted progressive collapse with a measured maximum vertical displacement of only one quarter of an inch （6.4 mm）。
土木工程外文翻译
<文献翻译一：原文>Strength of Concrete in Slabs, Investigates along Direction of Concreting ABSTRACTIn theory of concrete it is assumed that concrete composites are isotropic on a macro scale. For example, it is assumed that a floor sl ab’s or a beam’s strength is identical in all directions and its nonhomogeneity is random. Hence neither calculations of the load-bearing capacity of structural components nor the techniques of investigating concrete in structure in situ take into account to a sufficient degree the fact that the assumption about concrete isotropy is overly optimistic. The present research shows that variation in concrete strength along the direction of concreting has not only a qualitative effect (as is commonly believed), but also a significant quantitative effect. This indicates that concrete is a composite which has not been fully understood yet. The paper presents evaluations of ordinary concrete (OC) homogeneity along component thickness along the direction of concreting. The ultrasonic method and modified exponential heads with a point contact with concrete were used in the investigations [1-3].Keywords: Concrete; Compressive Strength of Concrete; Non-Destructive1. IntroductionIn a building structure there are components which are expected to have special properties but not necessarily in the whole cross section. Components under bending, such as beams and floor slabs are generally compressed in their upper zone and the concrete’s compressive strength is vital ma inly in this zone. The components are usually moulded in the same position in which they later remain in service, i.e. with their upper zone under compression. Concrete in the upper zone is expected to be slightly weaker than in the lower zone, but it is unclear how much weaker [4,5]. Also flooring slabs in production halls are most exposed to abrasion and impact loads in their upper zone which is not their strongest part. It is known from practice that industrial floors belong to the most often damaged building components.When reinforced concrete beams or floor slabs are to be tested they can be accessed only from their undersides and so only the bottom parts are tested and on this basis conclusions are drawn about the strength of the concrete in the whole cross section, including in the compressed upper zone. Thus a question arises: how large are the errors committed in this kind of investigations?In order to answer the above and other questions, tests of the strength of concrete in various structural components, especially in horizontally concreted slabs, were carried out. The variation of strength along the thickness of the components was analyzed.2. Research SignificanceThe research results presented in the paper show that the compressive strength of concrete inhorizontally formed structural elements varies along their thickness. In the top zone the strength is by 25% - 30% lower than the strength in the middle zone, and it can be by as much as 100% lower than the strength in the bottom zone. The observations are based on the results of nondestructive tests carried out on drill cores taken from the structure, and verified by a destructive method. It is interesting to note that despite the great advances in concrete technology, the variation in compressive strength along the thickness of structural elements is characteristic of both old (over 60 years old) concretes and contemporary ordinary concretes.3. Test MethodologyBefore Concrete strength was tested by the ultrasonic method using exponential heads with a point contact with concrete. The detailed specifications of the heads can be found in [2,3]. The heads’ frequency was 40 and 100 kHz and the diameter of their concentrators amounted to 1 mm.In order to determine the real strength distributions in the existing structures, cylindrical cores 80 mm or 114 mm diameter (Figure 2) were drilled from them in the direction of concreting. Then specimens with their height equal to their diameter were cut out of the cores.Ultrasonic measurements were performed on the cores according to the scheme shown in Figure3. Ultrasonic pulses (pings) were passed through in two perpendicular directions I and II in planes spaced every 10 mm. In this way one could determine how ping velocity varied along the core’s height, i.e. along the thickness of the tested component.In both test directions ping pass times were determined and velocities CL were calculated. The velocities from the two directions in a tested measurement plane were averaged.Subsequently, specimens with their height equal to their diameter of 80 mm were cut out of the cores. Aver-age ultrasonic pulse velocity CL for the specimen’s central zone was correlated with fatigue strength fc determined by destructive tests carried out in a strength tester.For the different concretes different correlation curves with a linear, exponential or power equation were obtained. Exemplary correlation curve equations are given below:Lc c L c C f L f C f 38.1exp 0951.01.003.56705.232621.4=⋅=-⨯=where:fc —the compressive strength of concrete MPa,CL —ping velocity km/s.The determined correlation curve was used to calculate the strength of concrete in each tested core cross section and the results are presented in the form of graphs illustrating concrete strength distribution along the thickness of the tested component. 4. Investigation of Concrete in Industrial FloorsAfter Floor in sugar factory’s raw materials storage hall Concrete in an industrial floor must have particularly good characteristics in the top layer. Since it was to be loaded with warehouse trucks and stored sugar beets and frequently washed the investigated concrete floor (built in 1944) was designed as consisting of a 150 mm thick underlay and a 50 mm thick surface layer and made of concrete with a strength of 20 MPa (concrete A).As part of the investigations eight cores, each 80 mm in diameter,were drilled from the floor. The investigations showed significant departures from the design. The concrete subfloor’s thickness varied from 40 to 150 mm. The surface layer was not made of concrete, but of cement mortar with sand used as the aggregate. Also the thickness of this layer was uneven, varying from 40 to 122mm. After the ultrasonic tests specimens with their height equal to their diameter of 80 mm were cut out of the cores. Two scaling curves: one for the surface layer and the other for the bottom concrete layer were determined.A characteristic concrete compressive strength distribution along the floor’s thickness is shown in Figure 4.Strength in the upper zone is much lower than in the lower zone: ranging from 4.7 to 9.8 MPa for the mortar and from 13.9 to 29.0 MPa for the concrete layer. The very low strength of the upper layer of mortar is the result of strong porosity caused by air bubbles escaping upwards during the vibration of concrete. Figure 5 shows the specimen’s porous top surface.Floor in warehouse hall with forklift truck transport The floor was built in 1998. Cellular concrete was used as for the underlay and the 150 mm thick surface layer was made of ordinary concrete with fibre (steel wires) reinforcement (concrete B). Cores 80 mm high and 80 mm in diameter were drilled from the surface layer. Ultrasonic measurements and destructive tests were performed as described above. Also the test results were handled in a similar way. An exemplary strength distribution along the floor’s thickness is shown in Figure 6.5. ConclusionsTests of ordinary concretes show unexpectedly greatly reduced strength in the upper zone of horizontally moulded structural components. This is to a large degree due to the vibration of concrete as a result of which coarse aggregate displaces downwards making the lower layers more compact while air moves upwards aerating the upper layers and thereby increasing their porosity. The increase in the concret e’s porosity results in a large drop in its compressive strength. Thanks to the use of the ultrasonic method and probes with exponential concentrators it could be demonstrated how the compressive strength of ordinary concrete is distributed along the thickness of structural components in building structures. It became apparent that the reduction in compressive strength in the compressed zone of structural components under bending and in industrial concrete floors can be very large (amounting to as much as 50% of the strength of the slab’s lower zone). Therefore this phenomenon should be taken into account at the stage of calculating slabs, reinforced concrete beams and industrial floors [6].The results of the presented investigations apply to ordinary concretes (OC) which are increasingly supplanted by self-compacting concretes (SCC) and high-performance concretes (HPC). Since no intensive vibration is required to mould structures from such concretes one can expect that they are much more homogenous along their thickness [7]. This will be known once the ongoing experimental research is completed.Bohdan StawiskiStrength of Concrete in Slabs, Investigates along Direction of Concreting[D]Institute of Building Engineering, Wroclaw University of Technology Wybrzeze Wyspianskiego, Wroclaw, Poland Received October 15, 2011; revised November 21, 2011; accepted November 30, 2011<文献翻译一：译文>混凝土强度与混凝土浇筑方向关系的研究摘要从理论上看，假设混凝土复合材料是各项同性的从宏观尺度上讲。
土木工程毕业设计外文翻译最终中英文
7 Rigid-Frame StructuresA rigid-frame high-rise structure typically comprises parallel or orthogonally arranged bents consisting of columns and girders with moment resistant joints. Resistance to horizontal loading is provided by the bending resistance of the columns, girders, and joints. The continuity of the frame also contributes to resisting gravity loading, by reducing the moments in the girders.The advantages of a rigid frame are the simplicity and convenience of its rectangular form.Its unobstructed arrangement, clear of bracing members and structural walls, allows freedom internally for the layout and externally for the fenestration. Rigid frames are considered economical for buildings of up to' about25 stories, above which their drift resistance is costly to control. If, however,a rigid frame is combined with shear walls or cores, the resulting structure is very much stiffer so that its height potential may extend up to 50 stories or more. A flat plate structure is very similar to a rigid frame, but with slabs replacing the girders As with a rigid frame, horizontal and vertical loadings are resisted in a flat plate structure by the flexural continuity between the vertical and horizontal components.As highly redundant structures, rigid frames are designed initially on the basis of approximate analyses, after which more rigorous analyses and checks can be made. The procedure may typically include the following stages:1. Estimation of gravity load forces in girders and columns by approximate method.2. Preliminary estimate of member sizes based on gravity load forces witharbitrary increase in sizes to allow for horizontal loading.3. Approximate allocation of horizontal loading to bents and preliminary analysisof member forces in bents.4. Check on drift and adjustment of member sizes if necessary.5. Check on strength of members for worst combination of gravity and horizontalloading, and adjustment of member sizes if necessary.6. Computer analysis of total structure for more accurate check on memberstrengths and drift, with further adjustment of sizes where required. This stage may include the second-order P-Delta effects of gravity loading on the member forces and drift..7. Detailed design of members and connections.This chapter considers methods of analysis for the deflections and forces for both gravity and horizontal loading. The methods are included in roughly the order of the design procedure, with approximate methods initially and computer techniques later. Stability analyses of rigid frames are discussed in Chapter 16.7.1 RIGID FRAME BEHAVIORThe horizontal stiffness of a rigid frame is governed mainly by the bending resistance of the girders, the columns, and their connections, and, in a tall frame, by the axial rigidity of the columns. The accumulated horizontal shear above any story of a rigid frame is resisted by shear in the columns of that story (Fig. 7.1). The shear causes the story-height columns to bend in double curvature with points of contraflexure at approximately mid-story-height levels. The moments applied to a joint from the columns above and below are resisted by the attached girders, which also bend in double curvature, with points of contraflexure at approximately mid-span. These deformations of the columns and girders allow racking of the frame and horizontal deflection in each story. The overall deflected shape of a rigid frame structure due to racking has a shear configuration with concavity upwind, a maximum inclination near the base, and a minimum inclination at the top, as shown in Fig.7.1.The overall moment of the external horizontal load is resisted in each story level by the couple resulting from the axial tensile and compressive forces in the columns on opposite sides of the structure (Fig. 7.2). The extension and shortening of the columns cause overall bending and associated horizontal displacements of the structure. Because of the cumulative rotation up the height, the story drift dueto overall bending increases with height, while that due to racking tends to decrease. Consequently the contribution to story drift from overall bending may, in. the uppermost stories, exceed that from racking. The contribution of overall bending to the total drift, however, will usually not exceed 10% of that of racking, except in very tall, slender,, rigid frames. Therefore the overall deflected shape of a high-rise rigid frame usually has a shear configuration.The response of a rigid frame to gravity loading differs from a simply connected frame in the continuous behavior of the girders. Negative moments are induced adjacent to the columns, and positive moments of usually lesser magnitude occur in the mid-span regions. The continuity also causes the maximum girder moments to be sensitive to the pattern of live loading. This must be considered when estimating the worst moment conditions. For example, the gravity load maximum hogging moment adjacent to an edge column occurs when live load acts only on the edge span and alternate other spans, as for A in Fig. 7.3a. The maximum hogging moments adjacent to an interior column are caused, however, when live load acts only on the spans adjacent to the column, as for B in Fig. 7.3b. The maximum mid-span sagging moment occurs when live load acts on the span under consideration, and alternate other spans, as for spans AB and CD in Fig. 7.3a.The dependence of a rigid frame on the moment capacity of the columns for resisting horizontal loading usually causes the columns of a rigid frame to be larger than those of the corresponding fully braced simply connected frame. On the other hand, while girders in braced frames are designed for their mid-span sagging moment, girders in rigid frames are designed for the end-of-span resultant hogging moments, which may be of lesser value. Consequently, girders in a rigid frame may be smaller than in the corresponding braced frame. Such reductions in size allow economy through the lower cost of the girders and possible reductions in story heights. These benefits may be offset, however, by the higher cost of the more complex rigid connections.7.2 APPROXIMATE DETERMINATION OF MEMBER FORCES CAUSED BY GRAVITY LOADSIMGA rigid frame is a highly redundant structure; consequently, an accurate analysis can be made only after the member sizes are assigned. Initially, therefore, member sizes are decided on the basis of approximate forces estimated either by conservative formulas or by simplified methods of analysis that are independent of member properties. Two approaches for estimating girder forces due to gravity loading are given here.7.2.1 Girder Forces—Code Recommended ValuesIn rigid frames with two or more spans in which the longer of any two adjacent spans does not exceed the shorter by more than 20 %, and where the uniformly distributed design live load does not exceed three times the dead load, the girder moment and shears may be estimated from Table 7.1. This summarizes the recommendations given in the Uniform Building Code [7.1]. In other cases a conventional moment distribution or two-cycle moment distribution analysis should be made for a line of girders at a floor level.7.2.2 Two-Cycle Moment Distribution [7.2].This is a concise form of moment distribution for estimating girder moments in a continuous multibay span. It is more accurate than the formulas in Table 7.1, especially for cases of unequal spans and unequal loading in different spans.The following is assumed for the analysis:1. A counterclockwise restraining moment on the end of a girder is positive anda clockwise moment is negative.2. The ends of the columns at the floors above and below the considered girder are fixed.3. In the absence of known member sizes, distribution factors at each joint aretaken equal to 1 /n, where n is the number of members framing into the joint in the plane of the frame.Two-Cycle Moment Distribution—Worked Example. The method is demonstrated by a worked example. In Fig, 7.4, a four-span girder AE from a rigid-frame bent is shown with its loading. The fixed-end moments in each span are calculated for dead loading and total loading using the formulas given in Fig, 7.5. The moments are summarized in Table 7.2.The purpose of the moment distribution is to estimate for each support the maximum girder moments that can occur as a result of dead loading and pattern live loading.A different load combination must be considered for the maximum moment at each support, and a distribution made for each combination.The five distributions are presented separately in Table 7.3, and in a combined form in Table 7.4. Distributions a in Table 7.3 are for the exterior supports A andE. For the maximum hogging moment at A, total loading is applied to span AB with dead loading only on BC. The fixed-end moments are written in rows 1 and 2. In this distribution only .the resulting moment at A is of interest. For the first cycle, joint B is balanced with a correcting moment of- (-867 + 315)/4 = - U/4 assigned to M BA where U is the unbalanced moment. This is not recorded, but half of it, ( - U/4)/2, is carried over to M AB. This is recorded in row 3 and then added to the fixed-end moment and the result recorded in row 4.The second cycle involves the release and balance of joint A. The unbalanced moment of 936 is balanced by adding-U/3 = -936/3 = -312 to M BA (row 5), implicitly adding the same moment to the two column ends at A. This completes the second cycle of the distribution. The resulting maximum moment at A is then given by the addition of rows 4 and 5, 936 - 312 = 624. The distribution for the maximum moment at E follows a similar procedure.Distribution b in Table 7.3 is for the maximum moment at B. The most severe loading pattern for this is with total loading on spans AB and BC and dead load only on CD. The operations are similar to those in Distribution a, except that the T first cycle involves balancing the two adjacent joints A and C while recording only their carryover moments to B. In the second cycle, B is balanced by adding - (-1012 + 782)/4 = 58 to each side of B. The addition of rows 4 and 5 then gives the maximum hogging moments at B. Distributions c and d, for the moments at joints C and D, follow patterns similar to Distribution b.The complete set of operations can be combined as in Table 7.4 by initially recording at each joint the fixed-end moments for both dead and total loading. Then the joint, or joints, adjacent to the one under consideration are balanced for the appropriate combination of loading, and carryover moments assigned .to the considered joint and recorded. The joint is then balanced to complete the distribution for that support.Maximum Mid-Span Moments. The most severe loading condition for a maximum mid-span sagging moment is when the considered span and alternate other spans and total loading. A concise method of obtaining these values may be included in the combined two-cycle distribution, as shown in Table 7.5. Adopting the convention that sagging moments at mid-span are positive, a mid-span total; loading moment is calculated for the fixed-end condition of each span and entered in the mid-span column of row 2. These mid-span moments must now be corrected to allow for rotation of the joints. This is achieved by multiplying the carryover moment, row 3, at the left-hand end of the span by (1 + 0.5 D.F. )/2, and the carryover moment at the right-hand end by -(1 + 0.5 D.F.)/2, where D.F. is the appropriate distribution factor, and recording the results in the middle column. For example, the carryover to the mid-span of AB from A = [(1 + 0.5/3)/2] x 69 = 40 and from B = -[(1+ 0.5/4)/2] x (-145) = 82. These correction moments are then added to the fixed-end mid-span moment to give the maximum mid-span sagging moment, that is, 733 + 40 + 82 = 855.7.2.3 Column ForcesThe gravity load axial force in a column is estimated from the accumulated tributary dead and live floor loading above that level, with reductions in live loading as permitted by the local Code of Practice. The gravity load maximum column moment is estimated by taking the maximum difference of the end moments in the connected girders and allocating it equally between the column ends just above and below the joint. To this should be added any unbalanced moment due to eccentricity of the girderconnections from the centroid of the column, also allocated equally between the column ends above and below the joint.第七章框架结构高层框架结构一般由平行或正交布置的梁柱结构组成，梁柱结构是由带有能承担弯矩作用节点的梁、柱组成。
土木工程外文翻译
3Building Engineering Ⅱ: Building Structures and SeismicResistanceTextPassageEarthquake Resistant Structural Systems1Rigid Frame StructuresRigid frame structures typically comprise floor diaphragms supported on beams which link to continuous columns (Figure 3-1). The joints between beam and columns are usually considered to be “rigid”. The frames are expected to carry the gravity loads throug h the flexural action of the beams and the prop ping action of the columns. Negative moments are induced in the beam adjacent to the columns causing the mid-span positive moment to be significantly less than in a simply supported span. In structures in which gravity loads dictate the design, economies in member size that arise from this effect tend to be offset by the higher cost of the rigid joints.Figure 3-1 Rigid frame structureLateral loads, imposed within the plane of the frame, are resisted through the development of bending moments in the beams and columns. Framed buildings often employ moment resistant frames in two orthogonal directions, in which case the column elements are common to both frames.Rigid frame structures are well suited to accommodate high levels of inelastic deformation. When a capacity design approach is employed, it is usual to assign the end zones of the flexural beams to accept the post-elastic deformation expected, and to design the column members such that their dependable strength is in excess of the over-strength capacity of the beam hinges, thereby ensuring they remain within their elastic response range regardless of the intensity of ground shaking. Rigid frame structures are, however, often quite flexible. When they are designed to be fully ductile, special provisions are often needed to prevent the premature onset of damage to non-structural components.Rigid frame construction is ideally suited for reinforced concrete building because of the inherent rigidity of reinforced concrete joints. The rigid frame form is also used for steel framebuildings. But moment resistant connections in steel tend to be costly. The sizes of the columns and girders at any level of a rigid-frame are directly influenced by the magnitude of the external shear at that level, and they therefore increase toward the base. Consequently, the design of the floor framing can not be repetitive as it is in some braced frames. A further result is that sometimes it is not possible in the lowest storeys to accommodate the required depth of girder within the normal ceiling space.While rigid frames of a typical scale that serve alone to resist lateral loading have an economic height limit of about 25 storeys, smaller scale rigid frames in the form of a perimeter tube, or typically scaled rigid frames in combination with shear walls or braced bents, can be economic up to much greater heights.2Infilled Frame StructuresInfilled frames (Figure 3-2) are the most usual form of construction for tall buildings of up to 30 storeys in height. Column and girder framing of reinforced concrete, or sometimes steel, is infilled by panels of brickwork, or cast-in-place concrete.Figure 3-2 Infilled frameWhen an infilled frame is subjected to lateral loading, the infill behaves effectively as a strut along its compression diagonal to brace the frame. Because the infills serve also as external walls or internal partitions, the system is an economical way of stiffening and strengthening the structure.The complex interactive behavior of the infill in the frame, and the rather random quality of masonry, had made it difficult to predicate with accuracy the stiffness and strength of an infilled frame. For these reasons, the use of the infills for bracing buildings has mainly been supplementary to the rigid frame action of concrete frames.3Shear WallsA shear wall is a vertical structural element that resists lateral forces in the plane of the wall through shear and bending. The high in plan stiffness and strength of concrete and masonry walls make them ideally suitable for bracing building as shear walls.A shear wall acts as a beam cantilevered out of the ground or foundation9 and, just as with a beam, part of its strength derives from its depth. Figure 3-3 shows two examples of a shear wall, one in a simple one-storey building and another in a multistorey building. In Figure 3-3a, the shear walls are oriented in one direction, so only lateral forces in this direction can be resisted. The roof serves as the horizontal diaphragm and must also be designed to resist the lateral loads and transfer them to the shear walls.a) End shear walls and interior shear wall b) Interior shear walls for bracing in two directionFigure 3-3 Shear wallFigure 3-3a also shows an important aspect of shear walls in particular and vertical elements in general. This is the aspect of symmetry that has a bearing on whether torsional effects will be produced. The shear walls in Figure 3-3a show the shear walls symmetrical in the plane of loading.Figure 3-3b illustrates a common use of shear walls at the interior of a multi-storey building. Because walls enclosing stairways, elevator shafts, and mechanical chases are mostly solid and run the entire height of the building, they are often used for shear walls. Although not as efficient from a strictly structural point of view, interior shear walls do leave the exterior of the building open for windows.Notice that in Figure 3-3b there are shear walls in both directions, which is a more realistic situation because both wind and earthquake forces need to be resisted in both directions. In this diagram, the two shear walls are symmetrical in one direction, but the single shear wall produces a nonsymmetric condition in the other since it is off center. Shear walls do not need to be symmetrical in a building, but symmetry is preferred to avoid torsional effects.If, in low-to medium-rise building, shear walls are combined with frames, it is reasonable to assume that the shear wall attract all the lateral loading so that the frame may be designed for only gravity loading. It is essentially important in shear wall structures to try to plan the wall layout so that the lateral load tensile stresses are suppressed by the gravity load stresses. This allows them to be designed to have only the minimum reinforcement.Since shear walls are generally both stiff and can be inherently robust, it is practical to design them to remain nominally elastic under design intensity loadings, particularly in regions of low or moderate seismicity. Under increased loading intensities, post-elastic deformations will develop within the lower portion of the wall (generally considered to extend over a height of twice the wall length above the foundation support system). Good post-elastic response can be readily achieved within this region of reinforced concrete or masonry shear walls through the provision of adequate confinement of the principal reinforcing steel and the prohibition of lap splices of reinforcing bars.Shear wall structures are generally quite stiff and, as such interstorey drift problems are rare and generally easily contained. The shear wall tends to act as a rigid body rotating about a plastic hinge which forms at the base of the wall. Overall structural deformation is thus a function of the wall rotation. Inter-storey drift problems which do occur are limited to the lower few floors.A major shortcoming with shear walls within buildings is that their size provides internal (or external) access barriers which may contravene the architectural requirements. This problem canbe alleviated by coupling adjacent more slender shear walls so a coupled shear wall structure is formed. The coupling beams then become shear links between the two walls and with careful detailing can provide a very effective, ductile control mechanism (Figure 3-4).Figure 3-4 Coupled shear wall structure4Braced FramesA braced frame is a truss system of the concentric or eccentric type in which the lateral forces are resisted through axial stresses in the members. Just as with a truss, the braced frame depends on diagonal members to provide a load path for lateral forces from each building element to the foundation. Figure 3-5 shows a simple one-storey braced frame. At one end of the building two bays are braced and at the other end only one bay is braced. This building is only braced in one direction and the diagonal member may be either in tension or compression, depending on which way the force is applied.a)Single story braced building b) Multistory braced buildingFigure 3-5 Braced frameFigure 3-5b shows two methods of bracing a multistorey building. A single diagonal compression member in one bay can be used to brace against lateral loads coming from either direction. Alternately, tension diagonals can be used to accomplish the same result, but they must be run both ways to account for the load coming from either direction.Braced framing can be placed on the exterior or interior of a building, and may be placed in one structural bay or several. Obviously, a braced frame can present design problems for windows and doorways, but it is a very efficient and rigid lateral force resisting s ystem.Two major shortcomings of braced systems are that their inclined diagonal orientation oftenconflicts with conventional occupancy use patterns; and secondly they often require careful detailing to avoid large local torsional eccentricities being introduced at the connections with the diagonal brace being offset from the frame node.5Wall-frame StructuresWhen shear walls are combined with rigid frames (Figure 3-6), the walls, which tend to deflect in a flexural configuration, and the frames, which tend to deflect in a shear mode, are constrained to adopt a common shape by the horizontal rigidity of the girders and slabs. As a consequence, the walls and frames interact horizontally, especially at the top, to produce a stiffer and stronger structure. The interacting wall-frame combination is appropriate for buildings in the 40-to-60-storey range, well beyond of rigid frame or shear wall alone.Figure 3-6 Wall-frame structureIn addition, less well-known feature of the wall- frame structure is that, in a carefully “tuned” structure, the shear in the frame can be made approximately uniform over the height, allowing the floor framing to be repetitive.Although the wall-frame structure is usually perceived as a concrete structural form, with shear walls and concrete frames, a steel counterpart using braced frames and steel rigid frames offers similar benefit of horizontal interaction. The braced frames behave with an overall flexural tendency to interact with the shear mode of the rigid frames.6Framed-Tube StructuresThe lateral resistance of framed-tube structures is provided by very stiff moment resisting frames that form a “tube” around the perimeter of the building. The frames c onsist of closely spaced column, 2~4m between centers, joined by deep spandrel girders (Figure 3-7). Although the tube carries all the lateral loading, the gravity load is shared between the tube and interior columns or walls. When lateral loading acts, the perimeter frames aligned in the direction of loading act as the “web” of the massive tube cantilever, and those normal to the direction of the loading act as the “flanges”.Figure 3-7 Frame-tube structureThe close spacing of the columns throughout the height of the structures is usually unacceptable at the entrance level. The columns are therefore merged, or terminated on a transfer beam, a few storeys above the base so that only a few, larger, more widely spaced columns continue to the base. The tube form was developed originally for buildings of rectangular plan; however, for other plan shapes, and has occasionally been used in circular and triangular configurations.The tube is suitable for both steel and reinforced construction and has been used for buildings ranging from 40 to more storeys. The highly repetitive pattern of the frames lends itself to prefabrication in steel, and to the use of rapidly gang forms in concrete, which make for rapid construction.The framed tube has been one of the most significant modern developments in high-rise structural form. It offers a relatively efficiently, easily constructed structure, appropriate for use up to the greatest of heights. Aesthetically, the tube’s externally evident form is regarded with mixed enthusiasm: some praise the logical clearly expressed structure while others criticize the girder-like façade as small-windowed and uninteresting repetitious.The tube structure’s structural efficiency, although hi gh, still leaves scope for improvement because the “flange” frames tend to suffer from “shear lag”; this result in mid-face “flange” columns being less stresses than the corner columns and, therefore, not contributing as fully as they could to the flange action.7Tube-in-Tube or Hull-Core StructuresThis variation of the framed tube consists of an outer framed tube, the “hull” together with an internal elevator and service core (Figure 3-8). The hull and the inner core act jointly in resisting both gravity and lateral loading. In a steel structure the core may consist of braced frames, whereas in a concrete structure it would consist of an assembly of shear walls.Figure 3-8 Tube-in-tubeTo some extent, the outer framed tube and the inner core interact horizontally as the shear and flexural components of a wall-frame structure, with the benefit of increase lateral stiffness. However, the structural tube usually adopts a highly dominant role because of its much greater structural depth.8Braced-Tube StructuresAnother way of improving the efficiency of the framed tube, thereby increasing its potential for greater heights as well as allowing greater spacing between the columns, is to add diagonal bracing to the faces of the tube. This arrangement was first used in a steel structure in 1969, in Chicago’s John Hancock Building (Figure 3-9). Because the diagonal of a braced tube are connected to the columns at each intersection, they virtually eliminate the effects of shear lag in both the flange and web frames. As a result, the structure behaves under lateral loading more like a braced frame, with greatly diminished bending in the members of the frames. Consequently, the spacing of the columns can be larger and the depth of the spandrels less, thereby allowing larger size windows than in the conventional tube structure.Figure 3-9 Braced-Tube StructuresIn the braced-tube structure the bracing contributes also to the improved performance of the tube in carrying gravity loading: differences between gravity load stresses in the columns are evened out by the braces transferring loading from the more highly to the less highly stressed columns.9Bundled-Tube StructuresThis structural form has been used for the Sears Tower in Chicago. The Sears Tower consists of four parallel rigid steel frames in each orthogonal direction, interconnected to form nine “bundled” tubes. As in the single-tube structure, the frames in the direction of lateral loading serves as “webs” of the vertical cantilever, with the normal f rame acting as “flanges”.The introduction of internal webs greatly reduces the shear lag in the flanges; consequently their columns are more evenly stressed than in the single-tube structure, and their contribution to the lateral stiffness is great. This allows columns of the frames to be spaced further apart and to be less obtrusive. In the Sears Tower, advantage was taken of the bundled form to discontinue some of the tubes, and so reduce the plan of the building at stages up to the height.New Words and Expressionsbraced frame 支撑框架braced-tube 桁架筒bundled-tube 束筒coupling beam 连梁coupled shear wall 联肢墙framed tube 框筒inter-storey drift 层间位移propping [ 'prɔpiŋ ] n. 支撑rigid frame 框架shear lag 剪力滞后spandrel [ 'spændrəl ] n. 上下层窗间墙stairway [ 'stεəwei ] n. 楼梯transfer beam 转换粱tube-in-tube / hull-core 筒中筒wall-frame structure 框架-剪力墙结构Exercises1Please name the types of earthquake resistant structural systems.2How does a rigid frame structure resist the gravity load and lateral load?3 Why are shear walls in both directions preferred?4 How are the loads shared between frame and tube in a framed-tube structure?Reading MaterialsPassage OneReinforced Concrete StructuresConcrete and reinforced concrete are used as building materials in every country. In many, including the United States and Canada, reinforced concrete is a dominant structural material in engineered construction. The universal nature of reinforced concrete construction stems from thewide availability of reinforcing bars and the constituents of concrete, gravel, sand, and cement, the relatively simple skills required in concrete construction, and the economy of reinforced concrete compared to other forms of construction. Concrete and reinforced concrete are used in bridges, buildings of all sorts, underground structures, water tanks, television towers, offshore oil exploration and production structures, dams, and even in ships.1Mechanics of Reinforced ConcreteConcrete is strong in compression but weak in tension. As a result, cracks develop whenever loads, or restrained shrinkage or temperature changes, give rise to tensile stresses in excess of the tensile strength of the concrete. In the plain concrete beam, the moments due to applied loads are resisted by an internal tension-compression couple involving tension in the concrete. Such a beam fails very suddenly and completely when the first crack forms. In a reinforced concrete beam, steel bars are embedded in the concrete in such a way that the tension forces needed for moment equilibrium after the concrete cracks can be developed in the bars.The construction of a reinforced concrete member involves building a form or mold in the shape of the member being built. The form must be strong enough to support the weight and hydrostatic pressure of the wet concrete, and any forces applied to it by workers, concrete buggies, wind, and so on. The reinforcement is placed in this form and held in place during the concreting operation. After the concrete has h ardened, the forms are removed.2Factors Affecting Choice of Concrete for a StructureThe choice of whether a structure should be built of concrete, steel, masonry, or timber depends on the availability of materials and on a number of value decisions.(1)EconomyFrequently, the foremost consideration is the overall cost of the structure. This is, of course, a function of the costs of the materials and the labor necessary to erect them. Frequently, however, the overall cost is affected as much or more by the overall construction time since the contractor and owner must allocate money to carry out the construction and will not receive a return on this investment until the building is ready for occupancy. As a result, financial savings due to rapid construction may more than offset increased material costs. Any measures the designer can take to standardize the design and forming will generally pay off in reduced overall costs.In many cases the long-term economy of the structure may be more important than the first cost. As a result, maintenance and durability are important c onsiderations.(2)Suitability of Material for Architectural and Structural F unctionA reinforced concrete system frequently allows the designer to combine the architectural and structural functions. Concrete has the advantage that it is placed in a plastic condition and is given the desired shape and texture by means of the forms and the finishing techniques. This allows such elements as flat plates or other types of slabs to serve as load-bearing elements while providing the finished floor and ceiling surfaces. Similarly, reinforced concrete wails can provide architecturally attractive surfaces in addition to having the ability to resist gravity, wind, or seismic loads. Finally, the choice of size or shape is governed by the designer and not by the availability of standard manufactured members.(3)Fire ResistanceThe structure in a building must withstand the effects of a fire and remain standing while the building is evacuated and the fire is extinguished. A concrete building inherently has a 1- to 3-hour fire rating without special fireproofing or other details. Structural steel or timber buildings must befireproofed to attain similar fire ratings.(4)RigidityThe occupants of a building may be disturbed if their building oscillates in the wind or the floors vibrate as people walk by. Due to the greater stiffness and mass of a concrete structure, vibrations are seldom a problem.(5)Low MaintenanceConcrete members inherently require less maintenance than do structural steel or timber members. This is particularly true if dense, air-entrained concrete has been used for surfaces exposed to the atmosphere, and if care has been taken in the design to provide adequate drainage off and away from the structure.(6)Availability of MaterialsSand, gravel, cement, and concrete mixing facilities are very widely available, and reinforcing steel can be transported to most job sites more easily than can structural steel. As a result, reinforced concrete is frequently used in remote areas.On the other hand, there are a number of factors that may cause one to select a material other than reinforced concrete. These include:(1)Low Tensile StrengthAs stated earlier, the tensile strength of concrete is much lower than its compressive strength (about 1/10), and hence concrete is subject to cracking. In structural uses this is overcome by using reinforcement to carry tensile forces and limit crack widths to within acceptable values. Unless care is taken in design and construction, however, these cracks may be unsightly or may allow penetration of water.(2)Forms and ShoringThe construction of a cast-in-place structure involves three steps not encountered in the construction of steel or timber structures. These are the construction of the forms, the removal of these forms, and propping or shoring the new concrete to support its weight until its strength is adequate. Each of these steps involves labor and/or materials which are not necessary with other forms of construction.(3)Relatively Low Strength per Unit of Weight or VolumeThe compressive strength of concrete is roughly 5% to 10% that of steel, while its unit density is roughly 30% that of steel. As a result, a concrete structure requires a larger volume and a greater weight of material than does a comparable steel structure. As a result, long-span structures are often built from steel.(4)Time-dependent Volume ChangesBoth concrete and steel undergo approximately the same amount of thermal expansion and contraction. Because there is less mass of Steel to be heated or cooled, and because steel is a better conductor than concrete, a steel structure is generally affected by temperature changes to a greater extent than is a concrete structure. On the other hand, concrete undergoes drying shrinkage, which, if restrained, may cause deflections or cracking. Furthermore, deflections will tend to increase with time, possibly doubling, due to creep of the concrete under sustained loads.3Building CodesThe first set of building regulations for reinforced concrete were drafted under the leadership of Professor Morsch of the University of Stuttgart and were issued in Prussia in 1904. Design regulations were issued in Britain, France, Austria, and Switzerland between 1907 and 1909.The American Railway Engineering Association appointed a Committee on Masonry in 1890. In 1903 this committee presented specifications for Portland cement concrete. Between 1908 and 1910 a series of committee reports led to the Standard Building Regulations for the Use of Reinforced Concrete published in 1910 by the National Association of Cement Users which subsequently became the American Concrete Institute.A Joint Committee on Concrete and Reinforced Concrete was established in 1904 by the American Society of Civil Engineers, American Society for Testing and Materials, the American Railway Engineering Association, and the Association of American Portland Cement Manufactures. This group was later joined by the American Concrete Institute. Between 1904 and 1910 the Joint Committee carried out research. A preliminary report issued in 1913 lists the more important papers and books on reinforced concrete published between 1898 and 1911. The final report of this committee was published in 1916. The history of reinforced concrete building codes in the United States was reviewed in 1954 by Kerekes and Reid.The design and construction of buildings is regulated by municipal bylaws called building codes. These exist to protect the public health and safety. Each city and town is free to write or adopt its own building code, and in that city or town, only that particular code has legal status. Because of the complexity of building code writing, cities in the United States generally base their building codes on one of three model codes: the Uniform Building Code, the Standard Building Code, or the Basic Building Code. These codes cover such things as use and occupancy requirements, fire requirements, heating and ventilating requirements, and structural design.The definitive design specification for reinforced concrete buildings in North America is the Building Code Requirements for Reinforced Concrete (ACI-318-95), which is explained in a Commentary.This code, generally referred to as the ACI Code, has been incorporated in most building codes in the United States and serves as the basis for comparable codes in Canada, New Zealand, Australia, and parts of Latin America. The ACI Code has legal status only if adopted in a local building code.Each nation or group of nations in Europe has its own building code for reinforced concrete. The CEB-FIP Model Code for Concrete Structures is intended to serve as the basis for future attempts to unify European codes. This code and the ACI Code are similar in many ways.Passage TwoEarthquake Induced Vibration of Structures1Seismicity and Ground MotionsThe most common cause of earthquakes is thought to be the violent slipping of rock masses along major geological fault lines in the Earth’s crust, or lithosphere. These fault lines divide the global crust into about 12 major tectonic plates, which are rigid, relatively cool slabs about 100km thick. Tectonic plates float on the molten mantle of the Earth and move relative to one another at the rate of 10 to 100mm/year.The basic mechanism causing earthquakes in the plate boundary regions appears to be that the continuing deformation of the crustal structure eventually leads to stresses which exceed the material strength. A rupture will then initiate at some critical point along the fault line and willpropagate rapidly through the highly stressed material at the plate boundary. In some cases, the plate margins are moving away from one another. In those cases, molten rock appears from deep in the Earth to fill the gap, often manifesting itself as volcanoes. If the plates are pushing together, one plate tends to dive under the other and, depending on the density of the material, it may resurface in the form of mountains and valleys. In both these scenarios, there may be volcanoes and earthquakes at the plate boundaries, both being caused by the same mechanism of movement in the Earth's crust. Another possibility is that the plate boundaries will slide sideways past each other, essentially retaining the local surface area of the plate. It is believed that about three quarters of the world's earthquakes are accounted for by this rubbing-striking-slipping mechanism, with ruptures occurring on faults on boundaries between tectonic plates. Earthquake occurrence maps tend to outline the plate boundaries. Such earthquakes are referred to as interplate earthquakes.Earthquakes also occur at locations away from the plate boundaries. Such events are known as intraplate earthquakes and they are much less frequent than interplate earthquakes. Because tectonic plates are not homogeneous or isotropic, areas of local high stress are developed as the plate attempts to move as a rigid body. Accordingly, rupture within the plate, and the consequent release of energy, are believed to give rise to these intraplate events.The po int in the Earth’s crustal system where an earthquake is initiated (the point of rupture) is called the hypocenter or focus of the earthquake. The point on the Earth’s surface directly above the focus is called the epicenter and the depth of the focus is the focal depth. Earthquake occurrence maps usually indicate the location of various epicenters of past earthquakes and these epicenters are located by seismological analysis of the effect of earthquake waves on strategically located receiving instruments called seismometers.When an earthquake occurs, several types of seismic wave are radiated from the rupture. The most important of these are the body waves (primary P and secondary S waves). P waves are essentially sound waves traveling through the Earth, causing particles to move in the direction of wave propagation with alternate expansions and compressions. They tend to travel through the Earth with velocities of up to 8000m/sec (up to 30 times faster than sound waves through air). S waves are shear waves with particle motion transverse to the direction of propagation. S waves tend to travel at about 60% of the velocity of P waves, so they always arrive at seismometers after the P waves. The-time lag between arrivals often provides seismologists with useful information about the distance of the epicenter from the recorder.2Measurement of EarthquakesEarthquakes are complex multi-dimensional phenomena, the scientific analysis of which requires measurement. Prior to the invention of modern scientific instruments, earthquakes were qualitatively measured by intensity, which differed from point-to-point. With the deployment of seismometers, an instrumental quantification of the entire earthquake event-the unique magnitude of the event-became possible.(1)MagnitudeThe total strain energy released during an earthquake is known as the magnitude of the earthquake and it is measured on the Richter scale. It is defined quite simply as the amplitude of the recorded vibrations on a particular kind of seismometer located at a particular distance from the epicenterM L = log A –log A o (3-1)。
土木工程外文翻译
土木工程外文翻译Overview of Engineering MechanicsAs we look around us we see a world full of ‘things’: machines, devices, tools; things that we have designed, built and used; things made of wood, metals, ceramics, and plastics. We know from experience that some things are better than others; they last longer, cost less, are quieter, look better, or are easier to use.当我们看我们周围的世界,我们会发现许多东西：机器、设备,:我们拥有的工具,我们设计、建造和使用的东西;有木头、金属、陶瓷、塑料制品。
我们从经验得知,有些事情是比其他人好,比他们更耐用,成本低,是安静的,看起来更好,或者是更容易使用。
Ideally, however, every such item has been designed according to some set of ‘functional requirements; as perceived by the designers—that is, it has been designed so as to answer the question, ‘Exactly what function should it perform?’In the world of engineering, the major function frequently is to support some type of loading due to weight, inertia, pressure etc. From the beams in our homes to the wings of an airplane, there must be an appropriate melding of materials, dimensions, and fastenings to produce structures that will perform their functions reliably for a reasonably cost over a reasonable lifetime.不管怎么样最理想的是每一个这样的项目根据一些规定的功能要求所设计,正如设计者所理解的那样,它被有计划的回答这个问题,“这个功能应该怎么正确完成?”世界上的一些工程，他主要功能是经常支持某一些由于自重，惯性压力等这些类型的荷载。
(完整版)土木工程毕业设计外文文献翻译
外文文献翻译Reinforced ConcreteConcrete and reinforced concrete are used as building materials in every country. In many, including the United States and Canada, reinforced concrete is a dominant structural material in engineered construction. The universal nature of reinforced concrete construction stems from the wide availability of reinforcing bars and the constituents of concrete, gravel, sand, and cement, the relatively simple skills required in concrete construction, and the economy of reinforced concrete compared to other forms of construction. Concrete and reinforced concrete are used in bridges, buildings of all sorts underground structures, water tanks, television towers, offshore oil exploration and production structures, dams, and even in ships.Reinforced concrete structures may be cast-in-place concrete, constructed in their final location, or they may be precast concrete produced in a factory and erected at the construction site. Concrete structures may be severe and functional in design, or the shape and layout and be whimsical and artistic. Few other building materials off the architect and engineer such versatility and scope.Concrete is strong in compression but weak in tension. As a result, cracks develop whenever loads, or restrained shrinkage of temperature changes, give rise to tensile stresses in excess of the tensile strength of the concrete. In a plain concrete beam, the moments about the neutral axis due to applied loads are resisted by an internal tension-compression couple involving tension in the concrete. Such a beam fails very suddenly and completely when the first crack forms. In a reinforced concrete beam, steel bars are embedded in the concrete in such a way that the tension forces needed for moment equilibrium after the concrete cracks can be developed in the bars.The construction of a reinforced concrete member involves building a from of mold in the shape of the member being built. The form must be strong enough to support both the weight and hydrostatic pressure of the wet concrete, and any forces applied to it by workers, concrete buggies, wind, and so on. The reinforcement is placed in this form and held in placeduring the concreting operation. After the concrete has hardened, the forms are removed. As the forms are removed, props of shores are installed to support the weight of the concrete until it has reached sufficient strength to support the loads by itself.The designer must proportion a concrete member for adequate strength to resist the loads and adequate stiffness to prevent excessive deflections. In beam must be proportioned so that it can be constructed. For example, the reinforcement must be detailed so that it can be assembled in the field, and since the concrete is placed in the form after the reinforcement is in place, the concrete must be able to flow around, between, and past the reinforcement to fill all parts of the form completely.The choice of whether a structure should be built of concrete, steel, masonry, or timber depends on the availability of materials and on a number of value decisions. The choice of structural system is made by the architect of engineer early in the design, based on the following considerations:1. Economy. Frequently, the foremost consideration is the overall const of the structure. This is, of course, a function of the costs of the materials and the labor necessary to erect them. Frequently, however, the overall cost is affected as much or more by the overall construction time since the contractor and owner must borrow or otherwise allocate money to carry out the construction and will not receive a return on this investment until the building is ready for occupancy. In a typical large apartment of commercial project, the cost of construction financing will be a significant fraction of the total cost. As a result, financial savings due to rapid construction may more than offset increased material costs. For this reason, any measures the designer can take to standardize the design and forming will generally pay off in reduced overall costs.In many cases the long-term economy of the structure may be more important than the first cost. As a result, maintenance and durability are important consideration.2. Suitability of material for architectural and structural function.A reinforced concrete system frequently allows the designer to combine the architectural and structural functions. Concrete has the advantage that it is placed in a plastic condition and is given the desired shapeand texture by means of the forms and the finishing techniques. This allows such elements ad flat plates or other types of slabs to serve as load-bearing elements while providing the finished floor and / or ceiling surfaces. Similarly, reinforced concrete walls can provide architecturally attractive surfaces in addition to having the ability to resist gravity, wind, or seismic loads. Finally, the choice of size of shape is governed by the designer and not by the availability of standard manufactured members.3. Fire resistance. The structure in a building must withstand the effects of a fire and remain standing while the building is evacuated and the fire is extinguished. A concrete building inherently has a 1- to 3-hour fire rating without special fireproofing or other details. Structural steel or timber buildings must be fireproofed to attain similar fire ratings.4. Low maintenance.Concrete members inherently require less maintenance than do structural steel or timber members. This is particularly true if dense, air-entrained concrete has been used for surfaces exposed to the atmosphere, and if care has been taken in the design to provide adequate drainage off and away from the structure. Special precautions must be taken for concrete exposed to salts such as deicing chemicals.5. Availability of materials. Sand, gravel, cement, and concrete mixing facilities are very widely available, and reinforcing steel can be transported to most job sites more easily than can structural steel. As a result, reinforced concrete is frequently used in remote areas.On the other hand, there are a number of factors that may cause one to select a material other than reinforced concrete. These include:1. Low tensile strength.The tensile strength concrete is much lower than its compressive strength ( about 1/10 ), and hence concrete is subject to cracking. In structural uses this is overcome by using reinforcement to carry tensile forces and limit crack widths to within acceptable values. Unless care is taken in design and construction, however, these cracks may be unsightly or may allow penetration of water. When this occurs, water or chemicals such as road deicing salts may cause deterioration or staining of the concrete. Special design details are required in such cases. In the case of water-retaining structures, special details and /of prestressing are required to prevent leakage.2. Forms and shoring. The construction of a cast-in-place structure involves three steps not encountered in the construction of steel or timber structures. These are ( a ) the construction of the forms, ( b ) the removal of these forms, and (c) propping or shoring the new concrete to support its weight until its strength is adequate. Each of these steps involves labor and / or materials, which are not necessary with other forms of construction.3. Relatively low strength per unit of weight for volume.The compressive strength of concrete is roughly 5 to 10% that of steel, while its unit density is roughly 30% that of steel. As a result, a concrete structure requires a larger volume and a greater weight of material than does a comparable steel structure. As a result, long-span structures are often built from steel.4. Time-dependent volume changes. Both concrete and steel undergo-approximately the same amount of thermal expansion and contraction. Because there is less mass of steel to be heated or cooled, and because steel is a better concrete, a steel structure is generally affected by temperature changes to a greater extent than is a concrete structure. On the other hand, concrete undergoes frying shrinkage, which, if restrained, may cause deflections or cracking. Furthermore, deflections will tend to increase with time, possibly doubling, due to creep of the concrete under sustained loads.In almost every branch of civil engineering and architecture extensive use is made of reinforced concrete for structures and foundations. Engineers and architects requires basic knowledge of reinforced concrete design throughout their professional careers. Much of this text is directly concerned with the behavior and proportioning of components that make up typical reinforced concrete structures-beams, columns, and slabs. Once the behavior of these individual elements is understood, the designer will have the background to analyze and design a wide range of complex structures, such as foundations, buildings, and bridges, composed of these elements.Since reinforced concrete is a no homogeneous material that creeps, shrinks, and cracks, its stresses cannot be accurately predicted by the traditional equations derived in a course in strength of materials forhomogeneous elastic materials. Much of reinforced concrete design in therefore empirical, i.e., design equations and design methods are based on experimental and time-proved results instead of being derived exclusively from theoretical formulations.A thorough understanding of the behavior of reinforced concrete will allow the designer to convert an otherwise brittle material into tough ductile structural elements and thereby take advantage of concrete’s desirable characteristics, its high compressive strength, its fire resistance, and its durability.Concrete, a stone like material, is made by mixing cement, water, fine aggregate ( often sand ), coarse aggregate, and frequently other additives ( that modify properties ) into a workable mixture. In its unhardened or plastic state, concrete can be placed in forms to produce a large variety of structural elements. Although the hardened concrete by itself, i.e., without any reinforcement, is strong in compression, it lacks tensile strength and therefore cracks easily. Because unreinforced concrete is brittle, it cannot undergo large deformations under load and fails suddenly-without warning. The addition fo steel reinforcement to the concrete reduces the negative effects of its two principal inherent weaknesses, its susceptibility to cracking and its brittleness. When the reinforcement is strongly bonded to the concrete, a strong, stiff, and ductile construction material is produced. This material, called reinforced concrete, is used extensively to construct foundations, structural frames, storage takes, shell roofs, highways, walls, dams, canals, and innumerable other structures and building products. Two other characteristics of concrete that are present even when concrete is reinforced are shrinkage and creep, but the negative effects of these properties can be mitigated by careful design.A code is a set technical specifications and standards that control important details of design and construction. The purpose of codes it produce structures so that the public will be protected from poor of inadequate and construction.Two types f coeds exist. One type, called a structural code, is originated and controlled by specialists who are concerned with the proper use of a specific material or who are involved with the safe design of a particular class of structures.The second type of code, called a building code, is established to cover construction in a given region, often a city or a state. The objective of a building code is also to protect the public by accounting for the influence of the local environmental conditions on construction. For example, local authorities may specify additional provisions to account for such regional conditions as earthquake, heavy snow, or tornados. National structural codes genrally are incorporated into local building codes.The American Concrete Institute ( ACI ) Building Code covering the design of reinforced concrete buildings. It contains provisions covering all aspects of reinforced concrete manufacture, design, and construction. It includes specifications on quality of materials, details on mixing and placing concrete, design assumptions for the analysis of continuous structures, and equations for proportioning members for design forces.All structures must be proportioned so they will not fail or deform excessively under any possible condition of service. Therefore it is important that an engineer use great care in anticipating all the probable loads to which a structure will be subjected during its lifetime.Although the design of most members is controlled typically by dead and live load acting simultaneously, consideration must also be given to the forces produced by wind, impact, shrinkage, temperature change, creep and support settlements, earthquake, and so forth.The load associated with the weight of the structure itself and its permanent components is called the dead load. The dead load of concrete members, which is substantial, should never be neglected in design computations. The exact magnitude of the dead load is not known accurately until members have been sized. Since some figure for the dead load must be used in computations to size the members, its magnitude must be estimated at first. After a structure has been analyzed, the members sized, and architectural details completed, the dead load can be computed more accurately. If the computed dead load is approximately equal to the initial estimate of its value ( or slightly less ), the design is complete, but if a significant difference exists between the computed and estimated values of dead weight, the computations should be revised using an improved value of dead load. An accurate estimate of dead load is particularly important when spans are long, say over 75 ft ( 22.9 m ),because dead load constitutes a major portion of the design load.Live loads associated with building use are specific items of equipment and occupants in a certain area of a building, building codes specify values of uniform live for which members are to be designed.After the structure has been sized for vertical load, it is checked for wind in combination with dead and live load as specified in the code. Wind loads do not usually control the size of members in building less than 16 to 18 stories, but for tall buildings wind loads become significant and cause large forces to develop in the structures. Under these conditions economy can be achieved only by selecting a structural system that is able to transfer horizontal loads into the ground efficiently.钢筋混凝土在每一个国家，混凝土及钢筋混凝土都被用来作为建筑材料。
(完整版)土木工程专业英语课文原文及对照翻译
Civil EngineeringCivil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities.土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。
此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。
Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities.土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。
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本科毕业设计（论文）外文翻译译文学生姓名：院（系）：专业班级：指导教师：完成日期：钢筋混凝土填充框架结构对拆除两个相邻的柱的响应作者：Mehrdad Sasani 美国波士顿东北大学，斯奈尔400设计中心MA02115收稿日期：2007年7月27日，修整后收稿日期2007年12月26日，录用日期2008年1月24日，网上上传日期2008年3月19日。
摘要：本文是评价圣地亚哥旅馆对同时拆除两根相邻的外柱的响应问题，圣地亚哥旅馆是个6层钢筋混凝土填充框架结构。
结构的分析模型应用了有限元法和以此为基础的分析模型来计算结构的整体和局部变形。
分析结果跟实验结果非常吻合。
当测量的竖向位移增加到为四分之一英寸（即6.4mm）的时候，结构就发生连续倒塌。
通过实验分析方法评价和讨论随着柱的移除而产生的变形沿着结构高度上的发展和荷载动态重分配。
讨论了轴向和弯曲的变形传播的不同。
结构横向和纵向的三维桁架在填充墙的参与下被认为是荷载重分配的主要构件。
讨论了两种潜在的脆性破坏模型（没有拉力加强的梁的脆断和有加筋肋的梁的挤出）。
分析评价了结构对额外的重力和无填充墙时的响应。
Elsevier有限责任公司对此文保留所有权利。
关键词：连续倒塌；荷载重分配；对荷载抵抗能力；动态响应；非线性分析；脆性破坏。
1. 介绍：作为减小由于结构的局部损坏而造成大量伤亡的可能性措施的一部分，美国总务管理局【1】和国防部【2】出台了一系列制度来评价结构对连续倒塌的抵抗力。
【3】定义连续倒塌为，由原始单元的局部破坏在单元间的扩展最终造成结构的整体或不成比例的大部破坏。
通过Ellingwood 和Leyendecker【4】建议的方法，ASCE/SEI 7定义了两种一般模型来减小结构设计时连续倒塌效应产生的损害，它们分为直接和间接的设计方法。
一般建筑规范和标准用增加结构的整体性的间接设计方法。
间接设计法也应用于美国国防部的降低连续倒塌设计和未归档设备标准中。
尽管间接设计法可以降低连续破坏的风险【6，7】，对基于此法设计的结构破坏后的表现的判断是不容易实现的。
有一种基于直接设计的方法通过研究瞬间消除受载构件，比如柱子，对结构的影响来评价结构的连续倒塌。
美国防部和国家事务管理局的规章是要求去除一个受荷构件，考虑其影响。
这样的规范目的是评价结构的整体性和结构的一个单元出现严重的毁坏时的分荷能力。
这种方法是研究结构受连续倒塌的影响的程度，但是事实上初始结构损伤的影响不止局限于某一根柱子。
在本论文中，应用通过实验证实的分析结果，评价圣地亚哥旅馆抵抗连续破坏的能力，实验中瞬间移除两个相邻的柱子，其中一个柱是拐角柱。
为了爆除这两个柱子，将炸药放在预先在柱子上钻的孔里面。
柱子然后再用几层保护材料包裹好，以避免爆炸时的冲击波和碎片影响结构的其他部分。
2. 建筑的特性圣地亚哥旅馆建造于1914年，在1924年又向南扩展了一部分，此部分包括两个分离的结构。
图.1是从南边看旅馆的样子。
注意这张照片，旅馆的第一和第三层被用黑色的布蒙了起来。
这个六层的旅馆是无延性的钢筋混凝土框架结构，其中还有由空心砖构成的填充外墙。
扩展部分的填充墙有两层共203mm厚。
第一层的楼高为6.0m，其他楼盖高为3.2m，顶楼高度为5.13m。
图.2为其中一个扩展部分的第二层。
图.3为对本建筑的实施计划，即瞬间爆除一层相邻的柱A2和A3，以评价其影响。
左图：图.1 圣地亚哥旅馆的南端视角，本论文研究其中心结构右图：图.2 扩展结构的第二层（南端视角）下图：图.3 拟对旅馆南扩展部分实施的柱的移除计划，第一层要被移除的柱用叉号标出如图.3所示楼盖系统纵向（南北向）有一个托梁。
根据两个混凝土构件受压的实验结果，对一个标准的混凝土柱，受压承载力为31MPa。
混凝土的弹性模量大概为26300MPa左右。
同样，通过横截面12.7mm的钢筋受拉实验，其屈服和极限抗拉强度分别为427和600MPa。
钢筋的极限变形为0.17。
钢筋的弹性模量近似为200000MPa。
这个建筑按计划将被爆破摧毁。
作为摧毁的一个步骤，第一层和第三层的填充墙被移除。
移除时上面没有活荷载。
所有的非结构部件包括隔墙、管道设备、家具都被事先搬走了，只有梁、柱、楼板梁和在边梁上的填充墙被留下。
3. 传感器布置混凝土和钢筋的应变传感器是用来测量梁和柱的应变变化的。
线性电位计用来测量整体和局部变形。
混凝土应变测量仪常900mm，最大应变为±0.02.钢筋应变测量仪应变极限为±0.2。
应变测量仪可以带到几百千赫兹。
电位计用来测量建筑中梁沿一端的转动和整体位移，这些以后将讲到。
电位计的分辨率为0.01mm，最大速度为1.0m/s，实验中最大记录速度为0.35m/s。
4. 有限元模型通过有限单元法，在软件SAP2000【8】中生成一个建筑模型。
梁和柱都被抽象成Bernoulli单元。
T和L型梁的翼缘计算宽度为四倍的较厚板的厚度【5】。
塑性铰可以发生在任何钢筋可能发生屈服的地方，包括单元的端点、加筋肋分离点和弯矩的屈服点。
在分析中，塑性铰的范围是构件高度的一半。
现行版本的SAP2000不能计算出单元斜裂缝的构成。
为了得出正确的构件挠曲刚度，反复做以下步骤：首先假设建筑的所有单元都是没有裂缝的；然后，需要弯矩同构件的出现裂缝的弯矩相比较。
分别降低板厚和梁的惯性矩35%，使需求弯矩大于裂缝出现弯矩。
梁外部出现裂缝的正负弯矩分别为58.2knM和37.9knM。
需要注意的是柱子没有裂缝出现。
再后，再按以上方法重新分析建筑和弯矩简图。
重复这些步骤直到所有的裂缝区域被鉴定和用模型表示出来。
除了两端区域建筑结构里的梁上部不配筋（图.4）。
例如，梁A1-A2在距A1点305mm以后，其上部不配筋（如图.4和5）。
为了确定出可能丧失挠曲强度的截面位置，将裂纹铰布置在上部没有配筋的可能的弯曲破坏点上。
塑性铰的挠曲强度设为于Mcr相等，当所受的弯矩达到Mcr时，该截面即发生破坏。
图.4 二层的梁A3-B3和梁A1-A2详细配筋情况楼盖系统有沿纵向（南北向）的次梁。
图.6所示为一典型的楼盖的横截面。
为了计算出次梁和板的可能的非线性响应，用梁单元为楼盖建立模型。
次梁按T型梁计算，翼缘的计算宽度为各自板厚的四倍【5】。
选取轴2和轴3的纵梁和其之间的一个宽20英寸的梁间的格栅为板的计算模型。
为了给出板沿横向的计算模型，同样用一个宽20英寸于横梁平行的梁。
在方形的板中其剪力流和梁单元的中的不一样。
所以其扭转刚度取为整个截面刚度的一半【9】。
图.5 梁的上部配筋弯曲位置（于梁A1-A2相似，在邻近建筑靠近柱A1的地方）图.6 典型的楼盖的次梁系统图.7 实验和分析的第二层柱A3的竖向位移建筑的2、4、5、6层有填充墙，并在门窗等开口位置有过梁，如前面提到的第1、三层的填充墙，在爆除前已经拆掉。
填充墙是用良好的空隙砖砌成的，空心砖的净空是其总大小的一半。
填充墙的平面效应增强了建筑的刚度和强度，并且影响建筑的对荷载反应即变形。
如果忽略墙的影响将得不到准确的建筑的刚度和强度。
在SAP2000中考虑了两种填充墙的形式：一种是用平面框架模型（模型A），另一种是FEMA365【10】中建议的受压杆件模型（模型B）。
4.1模型A是平面框架模型，但是，现行版本的SAP2000只能计算线性框架模型，不能计算裂缝的发展情况。
填充墙的抗拉强度大概为26psi，弹性模量为644ksi【10】。
由于裂缝的发展对填充墙的刚度影响很大，重复以下步骤来计算裂缝的形成：（1）假设填充墙是线性的而且没有开裂，运行非线性历史分析。
由于梁中的塑性铰的存在，梁中弯矩大于裂缝出现弯矩时候，对截面惯性矩有一个折减。
（2）判定填充墙出现的依据是看其应力于墙的抗拉强度大小关系。
（3）节点在拉应力大于抗拉强度的地方分离。
重复上面的步骤直到裂缝区域被确定。
4.2.模型B（受压杆件模型）如FEMA356【10】所述用受压杆件来代替填充墙，杆件的方向根据移除柱后的结构变形形式和开口位置确定。
4.3.柱的移除按以下步骤模拟柱的移除。
结构是在只受永久荷载下分析的，内力在柱端测定，将随着柱的移除而卸荷。
模型的建立是在移除第一层的柱A2、A3的情况下进行的。
结构同样是在永久荷载下进行静态分析的。
在此情况下，测得的柱端内力被当成永久外部荷载施加在结构上。
注意此分析结果跟第一步的分析是等价的。
第二步中大小相等方向相反的柱端力，被瞬间施加在原柱的位置上，然后进行动态分析。
4.4.实验和分析结果的比较结构计算最大竖向位移在第二层的柱A3上，图7所示为按模型A的实验和分析的梁A3竖向位移的比较。
实验数据是用三个粘在A3两端的传感器记录的。
实验和分析得到的最大位移分别是6.1mm和6.4mm，相差尽为4%。
实验和分析的位移产生所用时间分别为0.069S和0.066S。
分析结果显示永久位移为5.3mm，比实验结果小14%，实验结果为6.1mm。
图.8.第二层的柱A3在模型A和B下分别沿时间的竖向位移图.8.比较了第二层的柱A3分别在模型A和B下分析的沿时间的竖向位移。
由图中可以看出，按受压杆件模型（模型B）得出的最大竖向位移为11.4mm,比用模型A得出的结果高出约80%。
在图.7.可以看出按模型A得出的结果与实验结果是想接近的，B 模型得出的结构变形过高。
如果最大竖向位移偏大的话，填充墙开裂情况会更加严重，更偏向于受压杆件形成，模型A和模型B得出结果差异将减小。
图.9.比较了用模型A时第二层的柱A2的分析和实验的位移值。
同样，第一次达到最大位移值的实验和分析值非常接近，分析的永久位移值比实验的位移值略微低些。
图.10.所示为根据模型A得出的最大竖向位移的结构变形放大200倍后的情况。
图.9.第二层的柱A2竖向位移实验和分析结果比较图.10.按模型A，FEM分析的结构变形形式（第二层的实验得出变形形式也给出）通过实测得的变形形式在图中也用实线标出了。
在二层的梁A1-A2、A3-B3的上下端部应力重分配复杂的地方共用了14个电位计。
梁上部和对应的下部电位计接在一起用来测量梁的扭转变形。
用上下端部电位计的差值除以电位计的距离（沿梁高）。
分析推算的二层梁端部变形曲线如图中的曲线所示。
由图可以看出，分析的变形梁的变形曲线跟实验所得结果非常吻合。
根据模型A分析结果表明预示钢筋屈服的塑性铰只有两个，四个没有上部配筋的截面，到达屈服极限而开裂。
图.10.给出了所有的塑性铰及开裂位置。
Response of a reinforced concrete infilled-framestructure to removal of two adjacent columnsMehrdad Sasani_Northeastern University, 400 Snell Engineering Center, Boston, MA 02115,United StatesReceived 27 June 2007; received in revised form 26 December 2007;accepted 24 January 2008Available online 19 March 2008AbstractThe response of Hotel San Diego, a six-story reinforced concrete infilled-frame structure, is evaluated following the simultaneous removal of two adjacent exterior columns. Analytical models of the structure using the Finite Element Method as well as the Applied Element Method are used to calculate global and local deformations. The analytical results show good agreement with experimental data. The structure resisted progressive collapse with a measured maximum vertical displacement of only one quarter of an inch (6.4 mm). Deformation propagation over the height of the structure and the dynamic load redistribution following the column removal are experimentally and analytically evaluated and described. The difference between axial and flexural wave propagations is discussed. Three-dimensional Vierendeel (frame) action of the transverse and longitudinal frames with the participation of infill walls is identified as the major mechanism for redistribution of loads in the structure. The effects of two potential brittle modes of failure (fracture of beam sections without tensile reinforcement and reinforcing bar pull out) are described. The response of the structure due to additional gravity loads and in the absence of infill walls is analytically evaluated.c 2008 Elsevier Ltd. All rights reserved.Keywords: Progressive collapse; Load redistribution; Load resistance; Dynamic response; Nonlinear analysis; Brittle failure1. IntroductionAs part of mitigation programs to reduce the likelihood of mass casualtiesfollowing local damage in structures, the General Services Administration [1] and the Department of Defense [2] developed regulations to evaluate progressive collapse resistance of structures. ASCE/SEI 7 [3] defines progressive collapse as the spread of an initial local failure from element to element eventually resulting in collapse of an entire structure or a disproportionately large part of it. Following the approaches proposed by Ellingwood and Leyendecker [4], ASCE/SEI 7 [3] defines two general methods for structural design of buildings to mitigate damage due to progressive collapse: indirect and direct design methods. General building codes and standards [3,5] use indirect design by increasing overall integrity of structures. Indirect design is also used in DOD [2]. Although the indirect design method can reduce the risk of progressive collapse [6,7] estimation ofpost-failure performance of structures designed based on such a method is not readily possible. One approach based on direct design methods to evaluate progressive collapse of structures is to study the effects of instantaneous removal of load-bearing elements, such as columns. GSA [1] and DOD [2] regulations require removal of one load bearing element. These regulations are meant to evaluate general integrity of structures and their capacity of redistributing the loads following severe damage to only one element. While such an approach provides insight as to the extent to which the structures are susceptible to progressive collapse, in reality, the initial damage can affect more than just one column. In this study, using analytical results that are verified against experimental data, the progressive collapse resistance of the Hotel San Diego is evaluated, following the simultaneous explosion (sudden removal) of two adjacent columns, one of which was a corner column. In order to explode the columns, explosives were inserted into predrilled holes in the columns. The columns were then well wrapped with a few layers of protective materials. Therefore, neither air blast nor flying fragments affected the structure.2. Building characteristicsHotel San Diego was constructed in 1914 with a south annex added in 1924. The annex included two separate buildings. Fig. 1 shows a south view of the hotel. Note that in the picture, the first and third stories of the hotel are covered with black fabric. The six story hotel had a non-ductile reinforced concrete (RC) frame structure with hollow clay tile exterior infill walls. The infills in the annex consisted of two wythes (layers) of clay tiles with a total thickness of about 8 in (203 mm). The height of the first floor was about 190–800 (6.00 m). The height of other floors and that of the top floor were 100–600 (3.20 m) and 160–1000 (5.13 m), respectively. Fig. 2 shows the second floor of one of the annex buildings. Fig. 3 shows a typical plan of this building, whose response following the simultaneous removal (explosion) of columns A2 and A3 in the first (ground) floor is evaluated in this paper. The floor system consisted of one-way joists running in the longitudinal direction (North–South), as shown in Fig. 3. Based on compression tests of two concrete samples, the average concrete compressive strength was estimated at about 4500 psi (31 MPa) for a standard concrete cylinder. The modulus of elasticity of concretewas estimated at 3820 ksi (26 300 MPa) [5]. Also, based on tension tests of two steel samples having 1/2 in (12.7 mm) square sections, the yield and ultimate tensile strengths were found to be 62 ksi (427 MPa) and 87 ksi (600 MPa), respectively. The steel ultimate tensile strain was measured at 0.17. The modulus of elasticity of steel was set equal to 29 000 ksi (200 000 MPa). The building was scheduled to be demolished by implosion. As part of the demolition process, the infill walls were removed from the first and third floors. There was no live load in the building. All nonstructural elements including partitions, plumbing, and furniture were removed prior to implosion. Only beams, columns, joist floor and infill walls on the peripheral beams were present.3. SensorsConcrete and steel strain gages were used to measure changes in strains of beams and columns. Linear potentiometers were used to measure global and local deformations. The concrete strain gages were 3.5 in (90 mm) long having a maximum strain limit of ±0.02. The steel strain gages could measure up to a strain of ±0.20. The strain gages could operate up to a several hundred kHz sampling rate. The sampling rate used in the experiment was 1000 Hz. Potentiometers were used to capture rotation (integral of curvature over a length) of the beam end regions and global displacement in the building, as described later. The potentiometers had a resolution of about 0.0004 in (0.01 mm) and a maximum operational speed of about 40 in/s (1.0 m/s), while the maximum recorded speed in the experiment was about 14 in/s (0.35 m/s).4. Finite element modelUsing the finite element method (FEM), a model of the building was developed in the SAP2000 [8] computer program. The beams and columns are modeled with Bernoulli beam elements. Beams have T or L sections with effective flange width on each side of the web equal to four times the slab thickness [5]. Plastic hinges are assigned to all possible locations where steel bar yielding can occur, including the ends of elements as well as the reinforcing bar cut-off and bend locations. The characteristics of the plastic hinges are obtained using section analyses of the beams and columns and assuming a plastic hinge length equal to half of the section depth. The current version of SAP2000 [8] is not able to track formation of cracks in the elements. In order to find the proper flexural stiffness of sections, an iterative procedure is used as follows. First, the building is analyzed assuming all elements are uncracked. Then, moment demands in the elements are compared with their cracking bending moments, Mcr . The moment of inertia of beam and slab segments are reduced by a coefficient of 0.35 [5], where the demand exceeds the Mcr. The exterior beam cracking bending moments under negative and positive moments, are 516 k in (58.2 kN m) and 336 k in (37.9 kN m), respectively. Note that no cracks were formed in the columns. Then the building is reanalyzed and moment diagrams are re-evaluated. This procedure is repeated until all of the cracked regions are properly identified and modeled.The beams in the building did not have top reinforcing bars except at the end regions (see Fig. 4). For instance, no top reinforcement was provided beyond the bend in beam A1–A2, 12 inches away from the face of column A1 (see Figs. 4 and 5). To model the potential loss of flexural strength in those sections, localized crack hinges were assigned at the critical locations where no top rebar was present. Flexural strengths of the hinges were set equal to Mcr. Such sections were assumed to lose their flexural strength when the imposed bending moments reached Mcr.The floor system consisted of joists in the longitudinal direction (North–South). Fig. 6 shows the cross section of a typical floor. In order to account for potential nonlinear response of slabs and joists, floors are molded by beam elements. Joists are modeled with T-sections, having effective flange width on each side of the web equal to four times the slab thickness [5]. Given the large joist spacing between axes 2 and 3, two rectangular beam elements with 20-inch wide sections are used between the joist and the longitudinal beams of axes 2 and 3 to model the slab in the longitudinal direction. To model the behavior of the slab in the transverse direction, equally spaced parallel beams with 20-inch wide rectangular sections are used. There is a difference between the shear flow in the slab and that in the beam elements with rectangular sections modeling the slab. Because of this, the torsional stiffness is setequal to one-half of that of the gross sections [9].The building had infill walls on 2nd, 4th, 5th and 6th floors on the spandrel beams with some openings (i.e. windows and doors). As mentioned before and as part of the demolition procedure, the infill walls in the 1st and 3rd floors were removed before the test. The infill walls were made of hollow clay tiles, which were in good condition. The net area of the clay tiles was about 1/2 of the gross area. The in-plane action of the infill walls contributes to the building stiffness and strength and affects the building response. Ignoring the effects of the infill walls and excluding them in the model would result in underestimating thebuilding stiffness and strength.Using the SAP2000 computer program [8], two types of modeling for the infills are considered in this study: one uses two dimensional shell elements (Model A) and the other uses compressive struts (Model B) as suggested in FEMA356 [10] guidelines.4.1. Model A (infills modeled by shell elements)Infill walls are modeled with shell elements. However, the current version of the SAP2000 computer program includes only linear shell elements and cannot account for cracking. The tensile strength of the infill walls is set equal to 26 psi, with a modulus of elasticity of 644 ksi [10]. Because the formation ofcracks has a significant effect on the stiffness of the infill walls, the following iterative procedure is used to account for crack formation:(1) Assuming the infill walls are linear and uncracked, a nonlinear time history analysis is run. Note that plastic hinges exist in the beam elements and the segments of the beam elements where moment demand exceeds the cracking moment have a reduced moment of inertia.(2) The cracking pattern in the infill wall is determined by comparing stresses in the shells developed during the analysis with the tensile strength of infills.(3) Nodes are separated at the locations where tensile stress exceeds tensile strength. These steps are continued until the crack regions are properly modeled.4.2. Model B (infills modeled by struts)Infill walls are replaced with compressive struts as described in FEMA 356 [10] guidelines. Orientations of the struts are determined from the deformed shape of the structure after column removal and the location of openings.4.3. Column removalRemoval of the columns is simulated with the following procedure.(1) The structure is analyzed under the permanent loads and the internal forces are determined at the ends of the columns, which will be removed.(2) The model is modified by removing columns A2 and A3 on the first floor. Again the structure is statically analyzed under permanent loads. In this case, the internal forces at the ends of removed columns found in the first step are applied externally to the structure along with permanent loads. Note that the results of this analysis are identical to those of step 1.(3) The equal and opposite column end forces that were applied in the second step are dynamically imposed on the ends of the removed column within one millisecond [11] to simulate the removal of the columns, and dynamicanalysis is conducted.4.4. Comparison of analytical and experimental resultsThe maximum calculated vertical displacement of the building occurs at joint A3 in the second floor. Fig. 7 shows the experimental and analytical (Model A) vertical displacements of this joint (the AEM results will be discussed in the next section). Experimental data is obtained using the recordings of three potentiometers attached to joint A3 on one of their ends, and to the ground on the other ends. The peak displacements obtained experimentally and analytically (Model A) are 0.242 in (6.1 mm) and 0.252 in (6.4 mm), respectively, which differ only by about 4%. The experimental and analytical times corresponding to peak displacement are 0.069 s and 0.066 s, respectively. The analytical results show a permanent displacement of about 0.208 in (5.3 mm), which is about 14% smaller than the corresponding experimental value of 0.242 in (6.1 mm).Fig. 8 compares vertical displacement histories of joint A3 in the second floor estimated analytically based on Models A and B. As can be seen, modeling infills with struts (Model B) results in a maximum vertical displacement of joint A3 equal to about 0.45 in (11.4 mm), which is approximately 80% larger than the value obtained from Model A. Note that the results obtained from Model A are in close agreement with experimental results (see Fig. 7), while Model B significantly overestimates the deformation of the structure. If the maximum vertical displacement were larger, the infill walls were more severely cracked and the struts were more completely formed, the difference between the results of the two models (Models A and B) would be smaller.Fig. 9 compares the experimental and analytical (Model A) displacement of joint A2 in the second floor. Again, while the first peak vertical displacement obtained experimentally and analytically are in good agreement, the analytical permanent displacement under estimates the experimental value.Analytically estimated deformed shapes of the structure at the maximum vertical displacement based on Model A are shown in Fig. 10 with a magnification factor of 200. The experimentally measured deformed shape over the end regions of beams A1–A2 and A3–B3 in the second floorare represented in the figure by solid lines. A total of 14 potentiometers were located at the top and bottom of the end regions of the second floor beams A1–A2 and A3–B3, which were the most critical elements in load redistribution. The beam top and corresponding bottom potentiometer recordings were used to calculate rotation between the sections where the potentiometer ends were connected. This was done by first finding the difference between the recorded deformations at the top and bottom of the beam, and then dividing the value by the distance (along the height of the beam section) between the two potentiometers. The expected deformed shapes between the measured end regions of the second floor beams are shown bydashed lines. As can be seen in the figures, analytically estimated deformed shapes of the beams are in good agreement with experimentally obtained deformed shapes.Analytical results of Model A show that only two plastic hinges are formed indicating rebar yielding. Also, four sections that did not have negative (top) reinforcement, reached cracking moment capacities and therefore cracked. Fig. 10 shows the locations of all the formed plastic hinges and cracks.。