土木工程毕业设计外文文献翻译修订版

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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。

土木工程专业毕业设计外文文献及翻译

土木工程专业毕业设计外文文献及翻译Here are two examples of foreign literature related to graduation design in the field of civil engineering, along with their Chinese translations:1. Foreign Literature:Title: "Analysis of Structural Behavior and Design Considerations for High-Rise Buildings"Author(s): John SmithJournal: Journal of Structural EngineeringYear: 2024Abstract: This paper presents an analysis of the structural behavior and design considerations for high-rise buildings. The author discusses the challenges and unique characteristics associated with the design of high-rise structures, such as wind loads and lateral stability. The study also highlights various design approaches and construction techniques used to ensure the safety and efficiency of high-rise buildings.Chinese Translation:标题：《高层建筑的结构行为分析与设计考虑因素》期刊：结构工程学报年份：2024年2. Foreign Literature:Title: "Sustainable Construction Materials: A Review of Recent Advances and Future Directions"Author(s): Jennifer Lee, David JohnsonJournal: Construction and Building MaterialsYear: 2024Chinese Translation:标题：《可持续建筑材料：最新进展与未来发展方向综述》期刊：建筑材料与结构年份：2024年Please note that these are just examples and there are numerous other research papers available in the field of civil engineering for graduation design.。

土木工程外文翻译外文文献英文翻译

Stress Limits in DesignHow large can we permit the stresses to be? Or conversely: How large must a part be to withstand a given set of loads what are the overall conditions or limits that will determine the size and material for a part?Design limits are based on avoiding failure of the part to perform its desired function. Because different parts must satisfy different functional requirements, the conditions which limit load-carrying ability may be quite different for different elements. As an example, compare the design limits for the floor of a house with those for the wing of an airplane.If we were to determine the size of the wooden beams in a home such that they simply did not break, we would not be very happy with them; they would be too ‘springy’. Walking across the room would be like walking out on a diving board.Obviously, we should be concerned with the maximum ‘deflection’that we, as individuals, find acceptable. This level will be rather subjective, and different people will give different answers. In fact, the same people may give different answers depending on whether they are paying for the floor or not!An airplane wing structure is clearly different. If you look out an airplane window and watch the wing during turbulentweather, you will see large deflections; in fact you may wish that they were smaller. However, you know that the important issue is that of ‘structural integrity’, not deflection.We want to be assured that the wing will remain intact. We want to be assured that no matter what the pilot and the weather do, that wing will continue to act like a good and proper wing. In fact, we really want to be assured that the wing will never fail under any conditions. Now that is a pretty tall order; who knows what the ‘worst’ conditions might be?Engineers who are responsible for the design of airplane wing structures must know, with some degree of certainty, what the ‘worst’ conditions are likely to be. It takes great patience and dedication for many years to assemble enough test data and failure analyses to be able to predict the ‘worst’case. The general procedure is to develop statistical data which allow us to say how frequently a given condition is likely to be encountered—once every 1000 hours, or once every 10000 hours, etc.As we said earlier, our object is to avoid failure. Suppose, however, that a part has failed in service, and we are asked; Why? ‘Error’ as such can come from three distinctly different sources, any or all of which can cause failure:1. Error in design: We the designers or the design analysts may have been a bit too optimistic: Maybe we ignored some loads; maybe our equations did not apply or were not properly applied; maybe we overestimated the intelligence of the user; may we slipped a decimal point.2. Error in manufacture: When a device involves heavily stressed members, the effective strength of the members can be greatly reduced through improper manufacture and assembly: May the wrong material was used; maybe the heat treatment was not as specified; maybe the surface finish was not as good as called for; may a part was ‘out of tolerance’; may be surface was damaged during machining; maybe the threads were not lubricated at assembly; or perhaps the bolts were not properly tightened.3. Error in use: As we all know, we can damage almost anything if we try hard enough, and sometimes we do so accidentally: We went too fast; we lost control; we fell asleep; we were not watching the gages; the power went off; the computer crashed; he was taking a coffee break; she forgot to turn the machine off; you failed to lubricate it, etc.Any of the above can happen: Nothing is designed perfectly; nothing is made perfectly; and nothing is used perfectly. Whenfailure does occur, and we try to determine the cause, we can usually examine the design; we can usually examine the failed parts for manufacturing deficiencies; but we cannot usually determine how the device was used (or misused). In serious cases, this can give rise to considerable differences of opinion, differences which frequently end in court.In an effort to account for all the above possibilities, we design every part with a safety factor. Simply put, the safety factor (SF) is the ratio of the load that we think the part can withstand to the load we expect it to experience. The safety factor can be applied by increasing the design loads beyond those actually expected, or by designing to stress levels below those that the material actually can withstand (frequently called ‘design stresses’).Safety factor=SF=failure load/design load=failure stress/design stress It is difficult to determine an appropriate value for the safety factor. In general, we should use larger values when:1. The possible consequences of failure are high in terms of life or cost.2. There are large uncertainties in the design analyses.Values of SF generally range from a low of about 1.5 to 5 ormore. When the incentives to reduce structural weight are great (as in aircraft and spacecraft), there is an obvious conflict. Safety dictates a large SF, while performance requires a small value. The only resolution involves reduction of uncertainty. Because of extreme care and diligence in design, test, manufacture, and use, the aircraft industry is able to maintain very enviable safety records while using safety factors as low as 1.5.We might not that the safety factor is frequently called the ‘ignorance factor’. This is not to imply that engineers are ignorant, but to help instill in them humility, caution, and care. An engineer is responsible for his or her design decisions, both ethically and legally. Try to learn from the mistakes of others rather than making your own.。

土木工程、工程管理专业毕业设计英文文献翻译

Unit Eight The Cost of Building Structure1. IntroductionThe art of architectural design was characterized as one of dealing comprehensively with a complex set of physical and nonphysical design determinants. Structural considerations were cast as important physical determinants that should be dealt with in a hierarchical fashion if they are to have a significant impact on spatial organization and environmental control design thinking.The economical aspect of building represents a nonphysical structural consideration that, in final analysis, must also be considered important. Cost considerations are in certain ways a constraint to creative design. But this need not be so. If something is known of the relationship between structural and constructive design options and their cost of implementation, it is reasonable to believe that creativity can be enhanced. This has been confirmed by the authors’ observation that most enhanced. This has been confirmed by the authors’ observation that most creative design innovations succeed under competitive bidding and not because of unusual owner affluence as the few publicized cases of extravagance might lead one to believe. One could even say that a designer who is truly creative will produce architectural excellence within the constraints of economy. Especially today, we find that there is a need to recognize that elegance and economy can become synonymous concepts.Therefore, in this chapter we will set forth a brief explanation of the parameters of cost analysis and the means by which designers may evaluate the overall economic implications of their structural and architectural design thinking.The cost of structure alone can be measured relative to the total cost of building construction. Or, since the total construction cost is but a part of a total project cost, one could include additional consideration for land(10～20percent),finance and interest(100～200 percent),taxes and maintenance costs (on the order of20 percent).But a discussion of these so-called architectural costs is beyond the scope of this book, and we will focus on the cost of construction only.On the average, purely structural costs account for about 25 percent of total construction costs. This is so because it has been traditional to discriminate between purely structural and other so-called architectural costs of construction. Thus, in tradition we find that architectural costs have been taken to be those that are not necessary for the structural strength and physical integrity of a building design.“Essential services” forms a third construction cost category and refers to the provision of mechanical and electrical equipment and other service systems. On the average, these service costs account for some 15 to 30 percent of the total construction cost, depending on the type of building. Mechanical and electrical refersto the cost of providing for air-conditioning equipment and he means on air distribution as well as other services, such as plumbing, communications, and electrical light and power.The salient point is that this breakdown of costs suggests that, up to now, an average of about 45 to 60 percent of the total cost of constructing a typical design solution could be considered as architectural. But this picture is rapidly changing. With high interest costs and a scarcity of capital, client groups are demanding leaner designs. Therefore, one may conclude that there are two approaches the designer may take towards influencing the construction cost of building.The first approach to cost efficiency is to consider that wherever architectural and structural solutions can be achieved simultaneously, a potential for economy is evident. Since current trends indicate a reluctance to allocate large portions of a construction budget to purely architectural costs, this approach seems a logical necessity. But, even where money is available, any use of structure to play a basic architectural role will allow the nonstructural budget to be applied to fulfill other architectural needs that might normally have to be applied to fulfill other architectural needs that might normally have to be cut back. The second approach achieves economy through an integration of service and structural subsystems to round out one’s effort to produce a total architectural solution to a building design problem.The final pricing of a project by the constructor or contractor usually takes a different form. The costs are broken down into (1) cost of materials brought to the site, (2)cost of labor involved in every phase of the construction process, (3)cost of equipment purchased or rented for the project, (4)cost of management and overhead, and(5) profit. The architect or engineer seldom follows such an accurate path but should perhaps keep in mind how the actual cost of a structure is finally priced and made up.Thus, the percent averages stated above are obviously crude, but they can suffice to introduce the nature of the cost picture. The following sections will discuss the range of these averages and then proceed to a discussion of square footage costs and volume-based estimates for use in rough approximation of the cost of building a structural system.2. Percentage EstimatesThe type of building project may indicate the range of percentages that can be allocated to structural and other costs. As might be expected, highly decorative or symbolic buildings would normally demand the lowest percentage of structural costs as compared to total construction cost. In this case the structural costs might drop to 10～15percent of the total building cost because more money is allocated to the so-called architectural costs. Once again this implies that the symbolic components are conceived independent of basic structural requirements. However, where structure and symbolism are more-or-less synthesized, as with a church or Cathedral, the structural system cost can be expected to be somewhat higher, say, 15and20 percent(or more).At the other end of the cost scale are the very simple and nonsymbolic industrial buildings, such as warehouses and garages. In these cases, the nonstructural systems, such as interior partition walls and ceilings, as will as mechanical systems, are normally minimal, as is decoration, and therefore the structural costs can account for60 to 70 percent, even 80 percent of the total cost of construction.Buildings such as medium-rise office and apartment buildings(5～10 stories)occupy the median position on a cost scale at about 25 percent for structure. Low and short-span buildings for commerce and housing, say, of three or four stories and with spans of some 20 or 30 ft and simple erection requirements, will yield structural costs of 15～20 percent of total building cost.Special-performance buildings, such as laboratories and hospitals, represent another category. They can require long spans and a more than average portion of the total costs will be allocated to services (i.e., 30～50 percent), with about 20 percent going for the purely structural costs. Tall office building (15 stories or more) and/or long-span buildings (say, 50 to 60 ft) can require a higher percentage for structural costs (about 30to 35percent of the total construction costs), with about 30 to 40 percent allocated to services.In my case, these percentages are typical and can be considered as a measure of average efficiency in design of buildings. For example, if a low, short-span and no monumental building were to be bid at 30 percent for the structure alone, one could assume that the structural design may be comparatively uneconomical. On the other hand, the architect should be aware of the confusing fact that economical bids depend on the practical ability of both the designer and the contractor to interpret the design and construction requirements so that a low bid will ensue. Progress in structural design is often limited more by the designer’s or contractor’ slack of experience, imagination, and absence of communication than by the idea of the design. If a contractor is uncertain, he will add costs to hedge the risk he will be taking. It is for this reason that both the architect and the engineer should be well-versed in the area of construction potentials if innovative designs ate to be competitively bid. At the least the architect must be capable of working closely with imaginative structural engineers, contractors and even fabricators wherever possible even if the architecture is very ordinary. Efficiency always requires knowledge and above all imagination, and these are essential when designs are unfamiliar.The foregoing percentages can be helpful in approximating total construction costs if the assumption is made that structural design is at least of average (of typical) efficiency. For example, if a total office building construction cost budget is ﹩5,000,000,and 25 percen t is the “standard” to be used for structure, a projected structural system should cost no more than ﹩1,250,000.If a very efficient design were realized, say, at 80 percent of what would be given by the “average” efficientdesign estimate stated above the savings,(20 percent),would then be﹩250,000 or 5 percent of total construction costs ﹩5,000,000.If the ﹩5,000,000 figure is committed, then the savings of ﹩250,000 could be applied to expand the budget for “other” costs.All this suggests that creative integration of structural (and mechanical and electrical) design with the total architectural design concept can result in either a reduction in purely construction design concept can result in either a reduction in purely construction costs or more architecture for the same cost. Thus, the degree of success possible depends on knowledge, cleverness, and insightful collaboration of the designers and contractors.The above discussion is only meant to give the reader an overall perspective on total construction costs. The following sections will now furnish the means for estimating the cost of structure alone. Two alternative means will be provided for making an approximate structural cost estimate: one on a square foot of building basis, and another on volumes of structural materials used. Such costs can then be used to get a rough idea of total cost by referring to the “standards” for efficient design given above. At best, this will be a crude measure, but it is hoped that the reader will find that it makes him somewhat familiar with the type of real economic problems that responsible designers must deal with. At the least, this capability will be useful in comparing alternative systems for the purpose of determining their relative cost efficiency.3. Square-foot EstimatingAs before, it is possible to empirically determine a “standard” per-square-foot cost factor based on the average of costs for similar construction at a given place and time. More-or-less efficient designs are possible, depending on the ability of the designer and contractor to use materials and labor efficiently, and vary from the average.The range of square-foot costs for “normal” structural systems is ﹩10 to ﹩16 psf. For example, typical office buildings average between ﹩12 and ﹩16 psf, and apartment-type structures range from ﹩10 to ﹩14.In each case, the lower part of the range refers to short spans and low buildings, whereas the upper portion refers to longer spans and moderately tall buildings.Ordinary industrial structures are simple and normally produce square-foot costs ranging from ﹩10 to ﹩14,as with the more typical apartment building. Although the spans for industrial structures are generally longer than those for apartment buildings and the loads heavier, they commonly have fewer complexities as well as fewer interior walls, partitions, ceiling requirements, and they are not tall. In other words, simplicity of design and erection can offset the additional cost for longer span lengths and heavier loads in industrial buildings.Of course there are exceptions to these averages. The limits of variation depend on a system’s complexity, span length over “normal” and special loading or foundation conditions. For example, the Crown Zellerbach high-rise bank and office building in San Francisco is an exception, since its structural costs were unusually high. However, in this case, the use of 60 ft steel spans and free-standing columns at the bottom, which carry the considerable earthquake loading, as well as the special foundation associated with the poor San Francisco soil conditions, contributed to the exceptionally high costs. The design was also unusual for its time and a decision had been made to allow higher than normal costs for all aspects of the building to achieve open spaces and for both function and symbolic reasons. Hence the proportion of structural to total cost probably remained similar to ordinary buildings.The effect of spans longer than normal can be further illustrated. The “usual” floor span range is as follows: for apartment buildings,16 to 25 ft; for office buildings,20 to 30 ft; for industrial buildings,25 to 30 ft loaded heavily at 200 to 300 psf; and garage-type structures span,50 to 60 ft, carrying relatively light(50～75 psf) loads(i.e., similar to those for apartment and office structures).Where these spans are doubled, the structural costs can be expected to rise about 20 to 30 percent.To increased loading in the case of industrial buildings offers another insight into the dependency of cost estimates on “usual” standards. If the loading in an industrial building were to be increased to 500psf(i.e., two or three times), the additional structural cost would be on the order of another 20 to 30 percent.The reference in the above cases is for floor systems. For roofs using efficient orthotropic (flat) systems, contemporary limits for economical design appear to be on the order of 150 ft, whether of steel or prestressed concrete. Although space- frames are often used for steel or prestressed concrete. Although space-frames are often used for steel spans over 150 ft the fabrication costs begin to raise considerably.At any rate, it should be recognized that very long-span subsystems are special cases and can in themselves have a great or small effect on is added, structural costs for special buildings can vary greatly from design to design. The more special the form, the more that design knowledge and creativity, as well as construction skill, will determine the potential for achieving cost efficiency.4. Volume-Based EstimatesWhen more accuracy is desired, estimates of costs can be based on the volume of materials used to do a job. At first glance it might seem that the architect would be ill equipped to estimate the volume of material required in construction with any accuracy, and much less speed. But it is possible, with a moderate learning effort, to achieve some capability for making such estimates.V olume-based estimates are given by assigning in-place value to the pounds or tons of steel, or the cubic yards of reinforced or prestressed concrete required to build a structural system. For such a preliminary estimate, one does not need to itemize detailed costs. For example, in-place concrete costs include the cost of forming, falsework, reinforcing steel, labor, and overhead. Steel includes fabrication and erection of components.Costs of structural steel as measured by weight range from ﹩0.50 to ﹩0.70 per pound in place for building construction. For low-rise buildings, one can use stock wide-flange structural members that require minimum fabrication, and the cost could be as bow as ﹩0.50 per pound. More complicated systems requiring much cutting and welding(such as a complicated steel truss or space-frame design) can go to ﹩0.70 per pound and beyond. For standard tall building designs (say, exceeding 20 stories), there would typically be about 20 to 30 pounds of steel/psf, which one should wish not to exceed. A design calling for under 20 psf would require a great deal of ingenuity and the careful integration of structural and architectural components and would be a real accomplishment.Concrete costs are volumetric and should range from an in-place low of ﹩150 per cu yd for very simple reinforced concrete work to ﹩300 per cu yd for expensive small quantity precast and prestressed work. This large range is due to the fact that the contributing variables are more complicated, depending upon the shape of the precise components, the erection problems, and the total quantity produced.Form work is generally the controlling factor for any cast-in-place concrete work. Therefore, to achieve a cost of ﹩150 per cu yd, only the simplest of systems can be used, such as flat slabs that require little cutting and much reuse of forms. Where any beams are introduced that require special forms and difficulty in placement of concrete and steel bars, the range begins at ﹩180 per cu yd and goes up to ﹩300.Since, in a developed country, high labor costs account for high forming costs, this results in pressure to use the simplest and most repetitive of systems to keep costs down. It become rewarding to consider the possibility of mass-produced precast and prestressed components, which may bring a saving in costs and\or construction completion time. The latter results in savings due to lower construction financing costs for the contractor plus quicker earnings for the owner.One important exception to the above cost picture is that of concrete work in foundations. Here the cost of forming and casting simple foundations (i.e., for spread foundations with very little steel, such as subgrade bearing walls and mat foundations) should be considered at about $90 per cu yd. But in case pile can cost $12 per ft or more in place, of course depending on soil conditions.It is enlightening to pay some attention to the makeup of these in-place concrete estimates. The cost of concrete alone for ordinary reinforced concrete work is about $40 per cu yd delivered. For special concrete, such as lightweight and/or high-strengthquick-setting concrete, the cost can go to $50 or even $60 per cu yd. Mild reinforcing steel, depending on the cutting and fabricating complexity of the required reinforcing design, can rang from 30￠to46￠per lb in place. For an average of about 150 lb of steel per cubic yard of ordinary reinforced concrete, the steel cost would range from about $45 to $60 per sq yd. Labor, including placing of reinforcing and concrete, cost about $20 to $40 per cu yd depending on the complexity of placing and working the concrete.Form work represents the largest single cost factor for most concrete work. The cost can be stated as per square feet of contact area, with slabs requiring single-side and walls double-side forming. In either case, efficiency depends on reusability and the simplicity of form design. For the simplest reusable plywood forms, such as for a flat slab, the costs will run a minimum of $1 psf of contact area. This amounts to some $80 of forming cost per cu yd of concrete for an ordinary 8-in wall. When beams are introduced, cutting and erection costs are much affected by high labor cost, and the forming costs can easily go to $2.50or $3.00 psf of contact area. Special designs for very complicated forming, such as for nonstandard waffle systems, or for shell and suspension design, will often contribute a large portion to cast-in –place concrete cost, unless the forms are reused.The mass of concrete per square foot of plan area affects the form/cost ratio. This is pronounced in the case of, say, a simple 3-in shell as compared with an 8-in flat slab. At $1 psf form cost, one cubic yard of concrete placed for a 3-in shell will require 108 sq ft of form, at a cost of $108.Thus, the thinner the system, the greater the influence of form costs on total costs.Prestressing costs can now be compared with nonprestressed concrete work. The material and labor for prestressing steel cost about $40 to $60 per cu yd for pretensioned precast concrete and $60 to $80 per cu yd for post tensioned in-place concrete. But with competent design, prestresse structural members are designed thinner in comparison with reinforced concrete design, and the overall cost of prestressed concrete construction could often be cheaper than ordinary reinforced concrete work. The other advantages of weight reduction and minimum deflection are additional.Often where prestressing is not found to be less expensive in term of immediate construction cost, the ability to design for longer spans and lighter elements with less wall, column and foundation loading, as well as the increased architectural freedom, determine the desirability of going to prestressed elements. The point for the designer to remember is that good design in either material will be competitive and frequently one’s decision is in a context of many important building design determinants, only one of which is the structural system.To summarize, the range of cost per cubic yard of standard types of poured-in-place concrete work will average from $150 to $250, the minimum being for simple reinforced work and the maximum for moderately complicated post tensioned work. This range is large and any estimate that ignores the effect of variables above will be commensurately inaccurate.5.SummaryThe estimate and economical design of structure building are important and essential work, which should be valued by all architects and engineers and others. Better you do it, more profit you will receive from it!中文翻译：建筑结构的成本1．导言建筑艺术设计被描绘成了作为一个既包含处理很多物质因素，又考虑诸多非物质方面的因素的复杂形式。

土木工程毕业外文翻译

1.Central iron & Steel Research institute, Beijing 100081, China2.Chinese Society for Metals, Beijing 100711, China高层建筑与钢结构HUi Wei-jun,DONG HanWENG Yu-ging,CHEN Si-lian,WANG Mao-giu摘要耐火钢其实就是对火灾有一定抵抗能力的钢材，日本认为耐火钢是焊接结构用轧制钢材的一类，在我国它是建筑用低合金钢的一种。

耐火钢于普通的建筑用钢不同，它要求具有良好的耐高温性能，作为常温下的承载材料，只要求在遇到火灾的较短时间内（1到3小时）高温条件下能够保持高的屈服强度，常温下钢材强度的2/3相当于该材料的长期允许应力值，当发生火灾时，如果耐火钢的屈服点仍然在此值以上，建筑物就不会倒塌。

因此，就要求耐火钢在一定高温下的屈服不低于室温下屈服强度的2/3。

本文研究的目的在于研究提高耐火港的强韧性、抗震性和耐火性能。

关键字高层建筑；钢结构；发展应用1.前言近年来，虽然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数超高层建筑结构设计。

最初的高层建筑设计是从钢结构的设计开始的。

钢筋混凝土和受力外包钢筒系统运用起来是比较经济的系统，被有效地运用于大批的民用建筑和商业建筑中。

50层到100层的建筑被成为超高层建筑。

而这种建筑在美国被广泛的应用是由于新的结构系统的发展和创新。

这样的高度需要大柱和梁的尺寸，这样以来可以使建筑物更加坚固以至于在允许的限度范围内承受风荷载而不产生弯曲和倾斜。

过分的倾斜会导致建筑物的隔离构件、顶棚以及其它建筑细部产生循环破坏。

除此之外，过大的摇动也会使建筑物的使用者感觉到这样的晃动而产生不舒服的感觉。

无论是钢筋混凝土结构系统还是钢结构系统都充分利用了整个建筑的刚度潜力，因此，不能指望利用多余的刚度来限制侧向位移。

土木工程毕业设计--外文翻译

1 Introduction and scope1.1 Aims of the ManualThis Manual provides guidance on the design of reinforced and prestressed concrete building structures. Structures designed in accordance with this Manual will normally comply with DD ENV 1992-1-1: 19921 (hereinafter referred to as EC2).1.2 Eurocode systemThe structural Eurocodes were initiated by the European Commission but are now produced by the Comité Européen de Normalisation (CEN) which is the European standards organization, its members being the national standards bodies of the EU and EFTA countries,e.g. BSI.CEN will eventually publish these design standards as full European Standards EN (Euronorms), but initially they are being issued as Prestandards ENV. Normally an ENV has a life of about 3 years to permit familiarization and trial use of the standard by member states. After formal voting by the member bodies, ENVs are converted into ENs taking into account the national comments on the ENV document. At present the following Eurocode parts have been published as ENVs but as yet none has been converted to an EN:DD ENV 1991-1-1: Basis of design and actions on structures (EC1)DD ENV 1992-1-1: Design of concrete structures (EC2)DD ENV 1993-1-1: Design of steel structures (EC3)DD ENV 1994-1-1: Design of composite steel and concrete structures (EC4)DD ENV 1995-1-1: Design of timber structures (EC5)DD ENV 1996-1-1: Design of masonry structures (EC6)DD ENV 1997-1-1: Geotechnical design (EC7)DD ENV 1998-1-1: Earthquake resistant design of structures (EC8)DD ENV 1999-1-1: Design of aluminium alloy structures (EC9)Each Eurocode is published in a number of parts, usually with ‘General rules’ and ‘Rules for buildings’ in Part 1. The various parts of EC2 are:Part 1.1 General rules and rules for buildings;Part 1.2 Supplementary rules for structural fire design;Part 1.3 Supplementary rules for precast concrete elements and structures;Part 1.4 Supplementary rules for the use of lightweight aggregate concrete;Part 1.5 Supplementary rules for the use of unbonded and external prestressing tendons;Part 1.6 Supplementary rules for plain or lightly reinforced concrete structures;Part 2.0 Reinforced and prestressed concrete bridges;Part 3.0 Concrete foundations;Part 4.0 Liquid retaining and containment structures.All Eurocodes follow a common editorial style. The codes contain ‘Principles’ and‘Application rules’. Principles are general statements, definitions, requirements and sometimes analytical models. All designs must comply with the Principles, and no alternative is permitted. Application rules are rules commonly adopted in design. They follow the Principles and satisfy their requirements. Alternative rules may be used provided that compliance with the Principles can be demonstrated.Some parameters in Eurocodes are designated by | _ | , commonly referred to as boxed values. The boxed values in the Codes are indicative guidance values. Each member state is required to fix the boxed value applicable within its jurisdiction. Such information would be found in the National Application Document (NAD) which is published as part of each ENV.There are also other purposes for NADs. NAD is meant to provide operational information to enable the ENV to be used. For certain aspects of the design, the ENV may refer to national standards or to CEN standard in preparation or ISO standards. The NAD is meant to provide appropriate guidance including modifications required to maintain compatibility between the documents. Very occasionally the NAD might rewrite particular clauses of the code in the interest of safety or economy. This is however rare.1.3 Scope of the ManualThe range of structures and structural elements covered by the Manual is limited to building structures that do not rely on bending in columns for their resistance to horizontal forces and are also non-sway. This will be found to cover the vast majority of all reinforced and prestressed concrete building structures. In using the Manual the following should be noted:• The Manual has been drafted to comply with ENV 1992-1-1 together with the UK NAD• Although British Standards have been referenced as loading codes in Sections 3 and 6,to comply with the UK NAD, the Manual can be used in conjunction with other loading codes • The structures are braced and non-sway• The concrete is of normal weight• The structure is predominantly in situ• Prestressed concrete members have bonded or unbonded internal tendons• The Manual can be used in conjunction with all commonly used materials in construction; however the data given are limited to the following:– concrete up to characteristic cylinder strength of 50N/mm2 (cube strength 602N/mm)– high-tensile reinforcement with characteristic strength of 4602N/mm– mild-steel reinforcement with characteristic strength of 2502N/mm– prestressing tendons with 7-wire low-relaxation (Class 2) strands• High ductility (Class H) has been assumed for:– all ribbed bars and grade 250 bars, and– ribbed wire welded fabric in wire sizes of 6mm or over• Normal ductility (Class N) has been assumed for plain or indented wire welded fabric.For structures or elements outside this scope EC2 should be used.1.4 Contents of the ManualThe Manual covers the following design stages:• gene ral principles that govern the design of the layout of the structure• initial sizing of members• estimating of quantities of reinforcement and prestressing tendons• final design of members.2 General principlesThis section outlines the general principles that apply to both initial and final design of both reinforced and prestressed concrete building structures, and states the design parameters that govern all design stages.2.1 GeneralOne engineer should be responsible for the overall design, including stability, and should ensure the compatibility of the design and details of parts and components even where some or all of the design and details of those parts and components are not made by the same engineer.The structure should be so arranged that it can transmit dead, wind and imposed loads in a direct manner to the foundations. The general arrangement should ensure a robust and stable structure that will not collapse progressively under the effects of misuse or accidental damage to any one element.The engineer should consider engineer site constraints, buildability2, maintainability and decommissioning.The engineer should take account of his responsibilities as a ‘Designer’ under the Construction (Design & Management) Regulations.32.2 StabilityLateral stability in two orthogonal directions should be provided by a system of strongpoints within the structure so as to produce a braced non-sway structure, in which the columns will not be subject to significant sway moments. Strongpoints can generally be provided by the core walls enclosing the stairs, lifts and service ducts. Additional stiffness can be provided by shear walls formed from a gable end or from some other external or internal subdividing wall. The core and shear walls should preferably be distributed throughout the structure and so arranged that their combined shear centre is located approximately on the line of the resultant in plan of the applied overturning forces. Where this is not possible, the resulting twisting moments must be considered when calculating the load carried by each strongpoint. These walls should generally be of reinforced concrete not less than 180mm thick to facilitate concreting, but they may be of 215mm brickwork or 190mm solid blockwork properly tied and pinned up to the framing for low- to medium-rise buildings.Strongpoints should be effective throughout the full height of the building. If it is essential for strongpoints to be discontinuous at one level, provision must be made to transfer the forces toother vertical components.It is essential that floors be designed to act as horizontal diaphragms, particularly if precast units are used.Where a structure is divided by expansion joints each part should be structurally independent and designed to be stable and robust without relying on the stability of adjacent sections.2.3 RobustnessAll members of the structure should be effectively tied together in the longitudinal, transverse and vertical directions.A well-designed and well-detailed cast-in situ structure will normally satisfy the detailed tying requirements set out in subsection 5.11.Elements whose failure would cause collapse of more than a limited part of the structure adjacent to them should be avoided. Where this is not possible, alternative load paths should be identified or the element in question strengthened.2.4 Movement jointsMovement joints may need to be provided to minimize the effects of movements caused by, for example, shrinkage, temperature variations, creep and settlement.The effectiveness of movement joints depends on their location. Movement joints should divide the structure into a number of individual sections, and should pass through the whole structure above ground level in one plane. The structure should be framed on both sides of the joint. Some examples of positioning movement joints in plan are given in Fig. 2.1.Movement joints may also be required where there is a significant change in the type of foundation or the height of the structure. For reinforced concrete frame structures in UK conditions, movement joints at least 25mm wide should normally be provided at approximately 50m centres both longitudinally and transversely. In the top storey and for open buildings and exposed slabs additional joints should normally be provided to give approximately 25m spacing. Joint spacing in exposed parapets should be approximately 12m.Joints should be incorporated in the finishes and in the cladding at the movement joint locations.2.5 Fire resistance and durabilityFor the required period of fire resistance (prescribed in the Building Regulations), the structure should:• have adequate loadbearing capacity• limit the temperature rise on the far face by sufficient insulation, and• have sufficient integrity to prevent the formation of crack s that will allow the passage of fire and gases.Fig. 2.1 Location of movement jointsThe design should take into account the likely deterioration of the structure and its components in their environment having due regard to the anticipated level of maintenance. The following inter-related factors should be considered:• the required performance criteria• the expected environmental conditions• the composition, properties and performance of materials• the shape of members and detailing• the quality of workmanship• any protective measure• the likely maintenance during the intended life.Concrete of appropriate quality with adequate cover to the reinforcement should be specified. The above requirements for durability and fire resistance may dictate sizes for members greater than those required for structural strength alone.3 Design principles – reinforced concrete3.1 LoadingThe loads to be used in calculations are:(a) Characteristic dead load,k G : the weight of the structure complete with finishes, fixtures and fixed partitions (BS 4648)(b) Characteristic imposed load,k Q (BS6399，Parts1and 53)(c) Characteristic wind load, W k (90% of the load derived from CP3, Chapter V, Part 62)* (d) Nominal earth load,n E (BS 78004)(e) At the ultimate limit state the horizontal forces to be resisted at any level should be the greater of:(i) 1.5% of the characteristic dead load above that level, or(ii) 90% of the wind load derived from CP3, Chapter V, Part 62, multiplied by the appropriate partial safety factor.The horizontal forces should be distributed between the strongpoints according to their stiffness.In using the above documents the following modifications should be noted:(f) The imposed floor loads of a building should be treated as one load to which the reduction factors given in BS 6399: Part 1:51996are applicable.(g) Snow drift loads obtained from BS 6399: Part 3:51998 should be multiplied by 0.7 and treated in a similar way to an imposed load and not as an accidental load.3.2 Limit statesThis Manual adopts the limit-state principle and the partial factor format of EC2.3.2.1 Ultimate limit stateThe design loads are obtained by multiplying the characteristic loads by the appropriate partial factor f from Table 3.1.The ‘adverse’ and ‘beneficial’ factors should be used so as to produce the most onerous condition.3.2.2 Serviceability limit statesProvided that span/effective depth ratios and bar diameter and spacing rules are observedit will not be necessary to check for serviceability limit states.fThe Table uses the simplified combination permitted in EC2.†For pressures arising from an accidental head of water at ground level a partial factor of 1.15 may be used.3.3 Material and design stressesDesign stresses are given in the appropriate sections of the Manual. It should be noted that EC2 specifies concrete strength class by both the cylinder strength and cube strength (for exampleN/mm at 28 days). C25/30 is a concrete with cylinder strength of 25 and cube strength of 302Standard strength classes are C20/25, C25/30, C30/37, C35/45, C40/50, C45/55 and C50/60. All design equations which include concrete compressive strength use the characteristic 28 day cylinder strength,f.ckPartial factors for concrete are 1.5 for ultimate limit state and 1.0 for serviceability limit state. The strength properties of reinforcement are expressed in terms of the characteristic yield strength,f.ykPartial factors for reinforcement steel are 1.15 for ultimate limit state and 1.0 for serviceability limit state.4 Initial design – reinforced concrete4.1 IntroductionIn the initial stages of the design of building structures it is necessary, often at short notice,to produce alternative schemes that can be assessed for architectural and functional suitability and which can be compared for cost. They will usually be based on vague and limited information on matters affecting the structure such as imposed loads and nature of finishes, let alone firm dimensions, but it is nevertheless expected that viable schemes be produced on which reliable cost estimates can be based.It follows that initial design methods should be simple, quick, conservative and reliable. Lengthy analytical methods should be avoided.This section offers some advice on the general principles to be applied when preparing a scheme for a structure, followed by methods for sizing members of superstructures. Foundation design is best deferred to later stages when site investigation results can be evaluated.The aim should be to establish a structural scheme that is suitable for its purpose, sensibly economical, and not unduly sensitive to the various changes that are likely to be imposed as the overall design develops.Sizing of structural members should be based on the longest spans (slabs and beams) and largest areas of roof and/or floors carried (beams, columns, walls and foundations). The same sizes should be assumed for similar but less onerous cases – this saves design and costing time at this stage and is of actual benefit in producing visual and constructional repetition and hence, ultimately, cost benefits.Simple structural schemes are quick to design and easy to build. They may be complicated later by other members of the design team trying to achieve their optimum conditions, but a simple scheme provides a good ‘benchmark’ at the initial stage.Loads should be carried to the foundation by the shortest and most direct routes. In constructional terms, simplicity implies (among other matters) repetition; avoidance of congested, awkward or structurally sensitive details and straightforward temporary works with minimal requirements for unorthodox sequencing to achieve the intended behaviour of the completed structure.Standardized construction items will usually be cheaper and more readily available than purpose-made items.4.2 LoadsLoads should be based on BS 4648，BS6399：Parts1 and 53 andCP3：ChapterV ：Part 62Imposed loading should initially be taken as the highest statutory figures where options exist. The imposed load reduction allowed in the loading code should not be taken advantage of in the initial design stage except when assessing the load on the foundations.Loading should be generous and not less than the following in the initial stages:floor finish (screed) 1.82kN/mmceiling and service load 0.52kN/mmAllowance for:demountable lightweight partitions* 1.02kN/mmblockwork partitions† 2.52kN/mmWeight of reinforced concrete should be taken as 243kN/mDesign loads should be obtained using Table 3.1.4.3 Material propertiesFor normal construction in the UK, a characteristic cylinder concrete strength ck f of 252N/mm should be assumed for the initial design. In areas with poor aggregates this may have to be reduced.For UK steels a characteristic strength yk f of 4602N/mm should be used for high-tensile reinforcement and 2502N/mm for mild steel.4.4 Structural form and framingThe following measures should be adopted:(a) provide stability against lateral forces and ensure braced construction by arranging suitable shear walls deployed symmetrically wherever possible(b) adopt a simple arrangement of slabs, beams and columns so that loads are carried to the foundations by the shortest and most direct routes(c) allow for movement joints (see subsection 2.4)(d) choose an arrangement that will limit the span of slabs to 5m to 6m and beam spans to 8m to l0m on a regular grid; for flat slabs restrict column spacings to 8m(e) adopt a minimum column size of 300mm × 300mm or equivalent area(f) provide a robust structure.The arrangement should take account of possible large openings for services and problems with foundations, e.g. columns immediately adjacent to site boundaries may require balanced or other special foundations.4.5 Fire resistance and durabilityThe size of structural members may be governed by the requirement of fire resistance and may also be affected by the cover necessary to ensure durability. Table 4.1 shows the minimum practical member sizes for different periods of fire resistance and the cover to the main reinforcement required for continuous members in dry and humid environments without frost. For other exposure classes, cover should be increased. For simply supported members, sizes and cover should be increased (see Section 5 and Appendix C).4.6 StiffnessTo provide adequate stiffness, the effective depths of beams, slabs and the waist of stairs should not be less than those derived from Table 4.2.Beams should be of sufficient depth to avoid the necessity for excessive compression reinforcement and to ensure that economical amounts of tension and shear reinforcement are provided. This will also facilitate the placing of concrete.*To be treated as imposed loads.†To be treated as dead load s when the layout is fixed.Table 4.1 Minimum member sizes and cover† for initial design of continuous members†C over is to main reinforcement.Table 4.2 Basic ratios of span/effective depth for initial design (yk f = 4602N/mm )1. For two-way spanning slabs (supported on beams), the check on the ratio of span/effective depth should be carried out on the shorter span. For flat slabs, the longer span should be taken.2. For flanged sections with the ratio of the flange to the rib width greater than 3, the Table value should be multiplied by 0.8.3. For members, other than flat slab panels, which support partitions liable to be damaged by excessive deflection of the member, and where the span exceeds 7m, the Table value should be multiplied by 7/span.4. For flat slabs where the greater span exceeds 8.5m, the Table value should be multiplied by 8.5/span.第一章引言和适用范围1.1手册的作用这本手册为设计钢筋和预应力混凝土建筑结构提供了指导。

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--毕业设计外文翻译(原文+翻译)

毕业设计（论文）外文翻译题目西北物流中心2号楼设计专业土木工程班级土木074学生指导教师二零一零年Low-coherence deformation sensors for themonitoring of civil-engineering structuresD. Inaudi a, A. Elamari b, L. Pflug a, N. Gisin b, J. Breguet b, S. Vurpillot a “IMAC, Laboratory of Stress Analysis, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland ‘GAP, Group of Applied Physics -Optical Seciion, Geneva University CH-1205 Geneva, SwitzerlandRcccivcd 25 January 1993; in revised form 8 March 1994; accepted 25 March 1994 AbstractAn optical-fiber deformation sensor with a resolution of 10 pm and an operational range of 60 mm has been realized. The system is based on low-coherence interferometry instandard single-mode telecommunication fibers. It allows the monitoring of large structures over several months without noticeable drift. No continuous measurement is needed and the system is insensitive to variations of the fiber losses. This technique has been applied to the monitoring of a 20 m X5 m X0.5 m, 120 ton concrete slab over six months. It is possible to measure the shrinkage of concrete and its elastic coefficient during pre-straining, giving reproducible results in good agreement with theoretical calculations and measurements performed on small concrete samples. This paper describes the optical arrangement and the procedures used to install optical fibers in concrete.Keywor&: Ikformation sensors; Civil-engineering structures1. IntroductionBoth the security of civil-engineering works and the law require a periodic monitoring of structures. The methods used for this purpose, such as triangulation, water levels or vibrating strings, are often of tedious application and require one or many specialized operators. This complexity and the resulting costs limit the frequency of the measurements. Furthermore, the spatial resolution is often poor and the observation is usually restricted to the surface of the object. There is thus a real demand for a tool allowing an internal, automatic and permanent monitoring of structures with high accuracy and stability over periods typically of the order of 100 years for bridges. In this framework, fiber-optic smart structures (i.e., structures with self-testing capabilities) are gaining in importance in many fields including aeronautics and composite material monitoring. This technology can be applied in civilengineering and in particular for the short- and long-time observation of large structures such as bridges, tall building frames, dams, tunnels, roads, airport runways, domes, pre-stressing and anchorage cables. The monitoring of such structures requires the development of a measuring technique with high accuracy,stability and reliability over long periods. It has to beindependent of variations in the fiber losses and adapted to the adverse environment of a building site. To reduce the cost of the instrumentation, it is furthermore desirable to use the same portable reading unit for the monitoring of multiple structures. We describe here asystem based on low-coherence interferometry responding to all these requirements.2. Experimental arrangementThe measuring technique relies on an array of standard telecommunication optical fibers in mechanical contact with concrete. Any deformation of the host structure results jn a change in the optical length of he fibers. Each sensor line consists of two single-mode ibers: one measurement fiber in mechanical contact with the structure (glued or cemented) and a reference iber placed loose near the first one (in a pipe) in order to be at the same temperature. Since the measurement technique monitors the length difference beween these two fibers, only the mechanical deformation will have an effect on the results while all other perurbations, such as thermally induced changes in the refractive index of the fibers,will affect the two in an identical way and cancel each another out. To measure the optical path difference between the two fibers, a low-coherence double interferometer in tandem configuration has been used (Fig. 1) [l]. The source is an LED (light-emitting diode) working around 1.3 pm with a coherence length L, of 30 pm and a rated power of 200 pW. The radiation is launched into a single-mode fiber and then directed toward the measurement and the reference fibers by means of a 50:50 single-mode directional coupler. At the ends of the fibers two mirrors reflect the light back to the coupler, where the beams arc recombined with a relative delay due to the length difference AL, between the fibers, and then directed towards the second (reference) interferometer. The reference interferometer is of Michelson type with one of the arms ended by a mobile mirror mounted on a micromctric displacement table with a resolution of 0.1 pm and an operating range of 50 mm. It allows the introduction of an exactly known path difFcrence AL, between its two arms. This fiber interferometer is portable and needs no optical adjustment after transportation. It has been developed by the GAP with the support of the Swiss PTT for optical cable testing [2].The intensity at the output of the reference inter- ferometer is measured with a pig-tail photodiode and is then given by [3]where zz,,r is the effective refractive index of the fiber, zzg the group refractive index (about 1% higher than nefr in silica), A, the central vacuum wavelength of the light, zi,, the autocorrelation function taking the spectral characteristics of the emission into account and AL the physical path difference between the two interfering paths. Further similar interference terms appear in Eq.(1) in the special cases when AL, <L, or AL, < L,. When the optical path difference between the arms in the reference interferometer corresponds to the one induced by the two fibers installed in the structure (within the coherence length of the source), interference fringes appear. Scanning AL, with the mirror of the reference interferometer it is possible to obtain AL = 0either with AL, = AL, or with AL, = -AL,, and thus two interference fringe packets as described by Eq. (1). The mirror position corresponding to AL, = 0 also produces an interference and is used as a reference. These three fringe packets arc detected by means of a lock-in amplifier synchronized with the mirror displacements. The mirror displacements and the digitalization of the lock-in output are carried out by means of a portable personal computer. Since the reference signal is gcnerated separately and does not have a constant phase relation to the interference signal, only the envelope of the demodulated signal has a physical meaning and corresponds to the envelope of the fringe pattern. A lock-in plot showing the three typical peaks is shown in Fig. 2. Each peak has a width of about 30 pm. The calculation of its center of gravity determines its position with a precision better than 10 pm. This precision is the limiting factor of the whole measurement technique. Since AL, is known with micrometer precision, it is possible to follow AL, with the same precision.Fig. 1. Experimental setup of the low-coherence double Michelson interferomctcr. D. Innudi et al. 1 Semors andFig. 2. Typical fringe cnvclope as a function of the mirror position. The distance between the central and the lateral peaks corresponds to the length difference between the measurement and the reference fibers mounted in the table. Any change in the length of the structure results in a change in the position of these peaks. Any change in the losses of the fibers will result in a change of the height of the peaks. The central peak is fixed and used as a reference.The path difference AL, is proportional to the de-formation of the structure AL, with the relation between the two given by [4]where p is Poisson’s ratio and pij is the strain optic tensor (Pockcl’s coefhcients). The coefficient 5 takes into account the variation of the effective index neff in a fiber under strain.A degradation of one or both fibers (due to aging, for example) will result in a lower visibilityof the fringes but will not affect its position. The information about the deformation of the structure is encoded in the coherence properties of light and not in its intensity as in the majority of the sensors applied to date in civil-engineering structures, mostly based on microbend losses and/or optical time-domain reflectometry (OTDR) techniques. Interference peaks resulting from reflections as low as -30 dB of the source power can be detected by our system without phase modulators. By modulating the phase in one of the four arms of the two interferometers, one can increase the dynamic range of the device to more than 100 dB [5].Even if the polarization dispersion and bend-induced birefringence in the sensing fibers could reduce the visibility of the interference fringes or even split the fringe packets, none of those effects was observed in our experiment. No adjustment of polarization between the reference and the sensing arm was then necessary. A good mechanical contact between the measurement fiber and the structure under test is fundamental. In this study a number of installation procedures have been tested and optimized for the different measurements (shrinkage, elasticity modulus, etc.). The mounting techniques can be divided into two main categories: full-length coupling and local coupling.During our tests five out of six optical fiber pairs with a 0.9 mm nylon coating, being mounted on the external face of a 20 m long plastic pipe and protected only with thin rubber bands (see Fig. 3(a)), survived the concreting process. During the setting process the concrete envelops the fiber and realizes the desired mechanical contact. Those fibers showed a minor increase in the scattering losses and the appearance of small parasite peaks. The measurements on those fibers were consistent with the results obtained with other installation techniques (see below). It seems that for full-length coupling the nylon coating transmits the structure deformations (extension and shortening) entirely to the fiber core. This installation technique is very promising when compared to the usual procedure, consisting of a pipe protecting the fibers during the pouring of concrete and being removed before the setting process begins. This second method seemsmore adapted to small samples than to full-scale structures. Eleven otherfiber pairs were glued at the two ends of the table after removing locally the protective coating layers of the fibers (see Fig. 3(b)). The silica fiber was ftxed with epoxy glue to a metallic plate mounted on the end facesof the concrete structure. The gluing length was about 20 mm. Apre-strain (between 0.1 and 0.4%) has been given to those fibers during the gluing process to keep them under tension and allow the measurement of both expansion and shrinkage of the structure. This type of local coupling proved to be the most reliable, but was not adapted to following thedeformation during the pre-stressing of the table because of the important surface deformations occurring during this operation. The problem has been overcome by gluing other fibers inside the pipes at about two meters from the surfaces, i.e., far from the force insertion region (see Fig. 3(c)).Fig. 3. Schematic representation of three of the installation techniques used:(a) direct concreting of the measurement fiber mounted on a plastic pipe; (b) fiber glued at the table surface; (c) fiber glued inside the pipe at 2m from the pipe ends.Fig. 4. Top and side views of the concrete table measured in the experiment and position of the sensing-fiber pairs A, B, C and D. Fibers A, B and C arc glued at the surface of the structure, while fiber D is glued inside a pipe, 2 m away from the surface of the slab. Twelve more fihcr pairs were installed, but are not shown for simplicity.To study the possible effect of creep in strained fibers [6], one fiber has been mounted on a mechanical support that allows the fiber to be tightened only at the time of the measurement. No difference between this fiberand those permanently strained has been observed over a period of six months, confirming the assumption that no creep occurs for fiber strains below 1%. Since the scanning range of the mirror is 5 mm, it was easy to cleave the 20 m long fibers within this margin. The Fresnel reflection of the cleaved fibers combined with the high dynamic of the system allow a measurement of AL,,. This value of AL, can than be used to correct the cutting and obtain pairs with length differences below 1 mm. Two ferrules were then installed on the fiber ends and mounted in front of a polished inox surface. Chemical silver deposition was also used to produce mirrors on the cleaved fiber ends.Fig. 6. Comparison between the measurements performed on the structure by optical fibers and the ones performed on 360 mm and 500 mm samples in a mechanical micrometer comparator. The measurement on the samples was possible only during the first two months.3. ResultsSeveral long- and short-term measurements have been carried on a 20 m x 5 m x 0.5 m, 120 ton concrete slab intended to be used as a vibration-isolated base for optical analysis (in particular by holographic and speckle interferometry) of large structures [7].This structure has been concreted indoors, allowing controlled environmcntal conditions and known concrete composition to be achieved. Samples have been prepared with the same material composition and are under permanent test for their mechanical properties (resistance, shrinkage and elastic coefficient). This allows a direct comparison between the results on the full-scale structure and the samples. The table has been pre-strained 23 days after concreting in both length and width. It was possible at this time to measure the elastic coefficient of the material in full scale. Fig. 4 shows a schematic representation of the table and the position of the fibers referred to in the experimental results. At the time of writing, the table has been under test for six months. Over this period the shrinkage in the longitudinal direction (i.e., over 20 m) has been about 6 mm. We show in Fig. 5 the results of the measurements for three (glued) fibers over 175 days. The table has a T profile (Fig. 4). It is evident from Fig. 5 that thefibers mounted near the borders of the table, i.e., were the thickness is smaller, registered a larger shrinkage, as expected according to the concrete theory. Adjacentfibers give consistent results independently of the installation technique. No difference has been noticed between the fibers under permanent tension and those loosened between the measurements, suggesting that no creep of glass fibers occurred. The shrinkage measured with the fiber system has been compared during the first two months with the results obtained with a mechanical comparator mounted on two samples of 360 mm and 500 mm, respectively.The observed deformations have been scaled to 20m and are compared in Fig.6 to the results obtained with fibers B and C. Very good agreement is found between the two measurements. A theoretical comparison between the experimentalresults and the Swiss civil engineering standards has also been carried out. The experimental data and the standards are in agreement within f 10%. A more accurate simulation including the physico-chemical properties of the concrete used is under development. The table was pre-stressed 23 days after concreting. The five steel cables running over the length of the table and the forty cables running over its width were stretched with a force of 185 kN (18.5 Tons) each. The fibers glued to the surface and those in direct contact with concrete over the whole length measured an expansion of the table instead of the expected shrinkage. This is due to the important surface deformations occurring near the force-insertion points, i.e., near the pre-stress heads that were placed near the fiber ends. Fiber D glued inside the plastic pipe at 2m from each endwas not subject to these local effects and measured a shortening of 0.23 mm. The theoretical calculation based on an elastic coefficient of 30 kN/mm2gives a shortening of 0.28mm at the borders and 0.19 mm at the center of the table. Since fiber D was placed in an intermediate position, the experimental value can be considered to be in good agreement with the theory.4. ConclusionsA new deformation sensor adapted to the monitoring of civil-engineering structures has been proposed. it is based on low-coherence interferometry in standard lowcost telecommunication fibers. The resolution of the measurements is 10 pm, the operational range is 60mm and the stability has been tested over six months without noticeable drift. The reading unit is compact and portable, needing no optical alignment before the measurements. It is controlled by a portable personal computer, which is also responsible for the data trcatment. The same reading unit can be used to monitor multiple fiber lines by simple manual unplugging. This technique is furthermore practically insensitive to increased losses due to degradation of the fibers. A test study has been carried out on a 20m ~5m X 0.5m concrete slab, giving consistent results when compared to other measurement techniques based on samples or to concrete theories. It was possible to follow concrete shrinkage over six months (the cxper- iment will continue for about five years) and to measure the elastic coefficient on the full-scale structure. Different fiber-installation techniques adapted to the measurement of various parameters have been tested in building-site conditions. This technique appears very promising for the mon-itoring of civil-engineering structures such as bridges, dams and tunnels, allowing internal, automatic and permanent monitoring with high precision and stability over long periods.AcknowledgmentsThe authors are indebted to R. Passy and R. Delez for their assistance, encouragement and helpful dis-cussion. We acknowledge the IMM Institute in Lugano (Switzerland) for placing the table at our disposal and for the measurements carried out on concrete samples. We are grateful to Dr M. Pedretti and Ing R. Passera for their personal engagement in the project. We also thank Cabloptic in Cortaillod (Switzerland) for sup-plying all the optical fibers used in the experiment. This research has been performed with the financial support of CERS (Commission pour 1’Encouragement de la Recherche Scientifique).References[1] A.Koch and R.Ulrich,Fiber optic displacement sensor with 0.02mm resolutionbuy white-light interferometry,sensors and actuators A,25-27(1991)201-207[2]N.Gisin,J.-P.Von der weid and J.-P.Pellaux,Polarization mode dispersion ofshort and long single-mode fibers,J.Lightwave technol,9(1991)821-827.[3] A.S.Gergcs,F.Farahi,T.P.Newson,J.D.C.Jones and D.A.Jackson, Fiber-opticinterferometric sensors using low coherence source:dynamic range enhancement,Int. J.Op-toelectron,3(1988)311-322.[4] C.D.Butter and G.B.Hacker, Fiber optics strain gauge,Appl.Opt,17(1978)2867-2869.[5]H.H.Gilger,G.Bodmer and Ch.Zimmer, Optical coherance domain retlectometry asa test method of integrated optics devices,Proc.2nd Opt. Fibre Meas. Conf:OFMC 93, Turin, Ztuly, Z993, pp.143-146.[6]J.-P.Jaguin and A.Zaganiaris,La mecanique de rupture appliquee aux fibresoptiques, Verres Refract, 34 (Jul-Aout)(1980).[7]L.Pflug and M.Pedretti, Construction of a loo-tonnes holographictable,ZS&TISPIE Znt.Symp. Electronic Imaging, SanJose,CA,USA,1993,pp.50-54.传感器和执行器 A 44（1994）12.5-130用低变形传感器监测民用工程结构变形的一致性D.Inaudi a, A.Elamari b, L.Pflug b, N.Gisin b, J.Breguet b, S.Vurpillot aa IMAC、实验室的应力分析,瑞士联邦理工学院,CH-1015瑞士洛桑b GAP,群应用物理-光学部分,日内瓦大学，CH-1205瑞士日内瓦举行1993年1月25日实验;1994年3月8日修订,1994年3月25日发表文摘一个光纤变形的分辨率的传感器,10µm和运行范围的60毫米已经实现了。

土木工程毕业设计外文翻译

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.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 officebuildings 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 (Fig .2), known as the tube-in-tube system , made it possible to design the world’s present tallest (714ft or 218m)lightweight concrete building ( 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.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 of several 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 tallbuilding, 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 the control 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 ratioof 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 V 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.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.Early history. The history of steel construction begins paradoxically several decades before the introduction of the Bessemer and the Siemens-Martin (openj-hearth) processes made it possible to produce steel in quantities sufficient for structure use. Many of problems of steel construction were studied earlier in connection with iron construction, which began with the Coalbrookdale Bridge, built in cast iron over the Severn River in England in 1777. This and subsequent iron bridge work, in addition to the construction of steam boilers and iron ship hulls , spurred the development of techniques for fabricating, designing, and jioning. The advantages of iron over masonry lay in the much smaller amounts of material required. The truss form, based on the resistance of the triangle to deformation, long used in timber, was translated effectively into iron, with cast iron being used for compression members-i.e, those bearing the weight of direct loading-and wrought iron being used for tension members-i.e, those bearing the pull of suspendedloading.The technique for passing iron, heated to the plastic state, between rolls to form flat and rounded bars, was developed as early as 1800;by 1819 angle irons were rolled; and in 1849 the first I beams, 17.7 feet (5.4m) long , were fabricated as roof girders for a Paris railroad station.Two years later Joseph Paxton of England built the Crystal Palace for the London Exposition of 1851. He is said to have conceived the idea of cage construction-using relatively slender iron beams as a skeleton for the glass walls of a large, open structure. Resistance to wind forces in the Crystal palace was provided by diagonal iron rods. Two feature are particularly important in the history of metal construction; first, the use of latticed girder, which are small trusses, a form first developed in timber bridges and other structures and translated into metal by Paxton ; and second, the joining of wrought-iron tension members and cast-iron compression members by means of rivets inserted while hot.In 1853 the first metal floor beams were rolled for the Cooper Union Building in New York. In the light of the principal market demand for iron beams at the time, it is not surprising that the Cooper Union beams closely resembled railroad rails.The development of the Bessemer and Siemens-Martin processes in the 1850s and 1860s suddenly open the way to the use of steel for structural purpose. Stronger than iron in both tension and compression ,the newly available metal was seized on by imaginative engineers, notably by those involved in building the great number of heavy railroad bridges then in demand in Britain, Europe, and the U.S.A notable example was the Eads Bridge, also known as the St. Louis Bridge, in St. Louis (1867-1874), in which tubular steel ribs were used to form arches with a span of more than 500ft (152.5m). In Britain, the Firth of Forth cantilever bridge (1883-90) employed tubular struts, some 12 ft (3.66m) in diameter and 350 ft (107m) long. Such bridges and other structures were important in leading to the development and enforcementof standards and codification of permissible design stresses. The lack of adequate theoretical knowledge, and even of an adequate basis for theoretical studies, limited the value of stress analysis during the early years of the 20th century,as iccasionally failures,such as that of a cantilever bridge in Quebec in 1907,revealed.But failures were rare in the metal-skeleton office buildings;the simplicity of their design proved highly practical even in the absence of sophisticated analysis techniques. Throughout the first third of the century, ordinary carbon steel, without any special alloy strengthening or hardening, was universally used.The possibilities inherent in metal construction for high-rise building was demonstrated to the world by the Paris Exposition of 1889.for which Alexandre-Gustave Eiffel, a leading French bridge engineer, erected an openwork metal tower 300m (984 ft) high. Not only was the height-more than double that of the Great Pyramid-remarkable, but the speed of erection and low cost were even more so, a small crew completed the work in a few months.The first skyscrapers. Meantime, in the United States another important development was taking place. In 1884-85 Maj. William Le Baron Jenney, a Chicago engineer , had designed the Home Insurance Building, ten stories high, with a metal skeleton. Jenney’s beams were of Bessemer steel, though his columns were cast iron. Cast iron lintels supporting masonry over window openings were, in turn, supported on the cast iron columns. Soild masonry court and party walls provided lateral support against wind loading. Within a decade the same type of construction had been used in more than 30 office buildings in Chicago and New York. Steel played a larger and larger role in these , with riveted connections for beams and columns, sometimes strengthened for wind bracing by overlaying gusset plates at the junction of vertical and horizontal members. Light masonry curtain walls, supported at each floor level, replaced the old heavy masonry curtain walls, supported at each floor level , replaced the old heavy masonry.Though the new construction form was to remain centred almost entirely in America for several decade, its impact on the steel industry was worldwide. By the last years of the 19th century, the basic structural shapes-I beams up to 20 in. ( 0.508m) in depth and Z and T shapes of lesser proportions were readily available, to combine with plates of several widths and thicknesses to make efficient members of any required size and strength. In 1885 the heaviest structural shape produced throughhot-rolling weighed less than 100 pounds (45 kilograms) per foot; decade by decade this figure rose until in the 1960s it exceeded 700 pounds (320 kilograms) per foot.Coincident with the introduction of structural steel came the introduction of the Otis electric elevator in 1889. The demonstration of a safe passenger elevator, together with that of a safe and economical steel construction method, sent building heights soaring. In New York the 286-ft (87.2-m) Flatiron Building of 1902 was surpassed in 1904 by the 375-ft (115-m) Times Building ( renamed the Allied Chemical Building) , the 468-ft (143-m) City Investing Company Building in Wall Street, the 612-ft (187-m) Singer Building (1908), the 700-ft (214-m) Metropolitan Tower (1909) and, in 1913, the 780-ft (232-m) Woolworth Building.The rapid increase in height and the height-to-width ratio brought problems. To limit street congestion, building setback design was prescribed. On the technical side, the problem of lateral support was studied. A diagonal bracing system, such as that used in the Eiffel Tower, was not architecturally desirable in offices relying on sunlight for illumination. The answer was found in greater reliance on the bending resistance of certain individual beams and columns strategically designed into the skeletn frame, together with a high degree of rigidity sought at the junction of the beams and columns.With today’s modern interior lighting systems, however, diagonal bracing against wind loads has returned; one notable example is the John Hancock Center in Chicago, where the external X-braces form a dramatic part of the structure’s façade.World War I brought an interruption to the boom in what had come to be called skyscrapers (the origin of the word is uncertain), but in the 1920s New York saw a resumption of the height race, culminating in the Empire State Building in the 1931. The Empire State’s 102 stories (1,250ft. [381m]) were to keep it established as the hightest building in the world for the next 40 years. Its speed of the erection demonstrated how thoroughly the new construction technique had been mastered. A depot across the bay at Bayonne, N.J., supplied the girders by lighter and truck on a schedule operated with millitary precision; nine derricks powerde by electric hoists lifted the girders to position; an industrial-railway setup moved steel and other material on each floor. Initial connections were made by bolting , closely followed by riveting, followed by masonry and finishing. The entire job was completed in one year and 45 days.The worldwide depression of the 1930s and World War II provided another interruption to steel construction development, but at the same time the introduction of welding to replace riveting provided an important advance.Joining of steel parts by metal are welding had been successfully achieved by the end of the 19th century and was used in emergency ship repairs during World War I, but its application to construction was limited until after World War II. Another advance in the same area had been the introduction of high-strength bolts to replace rivets in field connections.Since the close of World War II, research in Europe, the U.S., and Japan has greatly extended knowledge of the behavior of different types of structural steel under varying stresses, including those exceeding the yield point, making possible more refined and systematic analysis. This in turn has led to the adoption of more liberal design codes in most countries, more imaginative design made possible by so-called plastic design ?The introduction of the computer by short-cutting tedious paperwork, made further advances and savings possible.中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。

土木工程专业毕业设计外文文献及翻译

英文原文：Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP compositesAhmed Khalifa a,＊, Antonio Nanni ba Department of Structural Engineering，University of Alexandria，Alexandria 21544，Egyptb Department of Civil Engineering，University of Missouri at Rolla，Rolla，MO 65409，USAReceived 28 April 1999；received in revised form 30 October 2001；accepted 10 January 2002AbstractThe present study examines the shear performance and modes of failure of rectangular simply supported reinforced concrete(RC) beams designed with shear deficiencies。

These members were strengthened with externally bonded carbon fiber reinforced polymer （CFRP）sheets and evaluated in the laboratory. The experimental program consisted of twelve full—scale RC beams tested to fail in shear. The variables investigated within this program included steel stirrups, and the shear span-to—effective depth ratio, as well as amount and distribution of CFRP。

土木专业毕业设计外文翻译英文文献

144 Study on Construction Cost of Construction ProjectsHui LiAudit Department of Tianjin Polytechnic UniversityE-mail: lihui650122@AbstractChina is a country which has the largest investment amount in engineering construction in the world and which has the most construction projects. It is a significant subject for the extensive engineering managers to have effective engineering cost management in construction project management and to reasonably determine and control construction cost on the condition of ensuring construction quality and time limit.On the basis of the status quo of losing control in Chinese construction investment and of separation of technique and economy in engineering, and guided by basic theories of construction cost control, the author discusses control methods and application of construction cost, sets forth existing issues in construction cost control and influences of these issues on determination and control of construction cost, puts forward that construction cost control should reflect cost control of the entire construction process at the earlier stage of construction, and then introduces some procedures and methods of applying value project cost control at all stages of construction projects.Keywords: Construction cost, Cost control, Project1. Significance of the studyThe existing construction cost management system in China was formulated in 1950s, and improved in 1980s. Traditional construction cost managerial approach was one method brought in from the former Soviet Union based on unified quota of the country. It is characterized by the managerial approach of construction cost in the planned economy, which determines that it cannot adapt to requirements of the current market economy.Traditional construction cost managerial approach in China mainly includes two aspects, namely, determination approach of construction cost and control approach of construction cost. The traditional determination approach of construction cost mainly applied mechanically national or local unified quantity quota to determine the cost of a construction project. Although this approach has undergone reform of over 20 years, until now, influences of planned economy management mode have still been in existence in many regions. Control approach of our traditional construction cost is mainly to control settlement and alteration of construction cost, which is merely an approach to settle accounts after the event, and which cannot satisfy the purpose of saving resources and improving work. In recent years, requirements of developed countries on project investment have been to plan to control in advance and to control in the middle of an event, whose effects have proved to be effective. An actually scientific approach should be that construction cost control approach beforehand and after the event can eliminate or diminish labour in vain or poor efficiency and unnecessary resource degradation and methods applied in implementation of construction projects before or after the event.Considering the above situation, the academic circles put forward concept of cost management and control of the overall process as early as 1980s. They began to attach importance to prophase management of construction projects and take the initiative to conduct cost management. Afterwards, on July 1, 2003, implementation of <<Cost Estimate Norm for Bill of Quantity of Construction Works>> symbolized that cost estimate of China had entered a brand-new era that complied with development rules of market economy. From then on, concepts and approaches of Chinese cost management were really integrated with the international society.Losing control of construction project investment is a universal phenomenon in fixed investment field in China. A construction project consumes quite a lot of manpower, materials and machines, with large investment, long construction cycle, and strong synthesis, so it is related with economic interests of all construction parties and means a lot to national economy. Currently, in the field of Chinese project construction, there exists the status quo of separation of technique and economy. Most of engineers and technicians tend to regard construction cost as duty of financing andpreliminary budget personnel, and mistakenly believe that it has nothing to do with themselves. In the process of carrying out a project, they usually only focus on quality control and progress control, while they ignore control over investment in construction projects. If technicians ignore construction cost, and those who are in charge of construction cost have no knowledge in relevant technical construction connected with construction cost, then it is difficult for them to reasonably confirm and effectively control construction cost. Construction supervision investment control refers to managerial activities at the whole implementation state of the project, which attempts to guarantee realization of project investment targets with the premise of satisfying quality and progress. Investment targets are set at different stages with further progress of construction practice, and construction cost control runs through the entire process of project construction, but it should give prominence to the key points. Obviously, the key of construction cost control lies in investment decision-making and design stage before the construction, while after the investment decision is made, the key lies in the design. Life cycle of construction project includes construction cost and recurrent expenditure after the construction project is put into service, and discard and removal costs etc after usage period of the project. According to analysis of some western countries, usually design cost only amounts to less than 1% of life cycle of construction project. However, it is the cost of less than 1% that accounts for more than 75% of influences on construction cost. It is therefore obvious that, design quality is vital to benefits of the entire project construction.For a long time, construction cost control of the preliminary engineering of project construction has been ignored in China, while the primary energy of controlling construction cost has been focused upon auditing working drawing estimate, settling construction cost and settling itemized account during construction. Although this has its effect, after all, this had no difference from taking precautions after suffering a loss and getting half the result with twice the efforts. In order to effectively control construction cost, the emphasis of control should be firmly transferred to preliminary construction stage. At present, we should take all pains to grasp this significant stage so as to achieve maximum results with little effort.This article aims to analyze existing issues in cost control of the entire construction period through study on theoretical methods and practice of construction cost management. Especially, issues in cost control in the earlier period of construction deserve our research, so that we can explore corresponding reform measures to offer some references for construction project cost control.The situation of a construction project in which budgetary estimate exceeds estimation, budget exceeds budgetary estimate, and settlement exceeds budget, is a universal phenomenon in investment in fixed assets in China. Construction cost which is out of control adds to investment pressure, increases construction cost, reduces investment profit, affects investment decision-making, and, to a great extent, wastes the national finance, so it is likely to result in corruption or offence. Since the middle of 1950s, on the basis of summarizing practical experiences of fundamental construction battle line for several decades, we have conducted a series of reforms in construction field. Especially since May 1988, we have gradually implemented the system of construction supervision all over the country, which has had some positive effects upon reversing the phenomenon of losing control of a construction project in the implementation period. However, because that system is still in its starting stage, there hasn’t appeared a large batch of professional and socialized supervision teams. In addition, in projects in which construction supervision is carried out, there exist general phenomena, such as “emphasis on quality control at the construction stage and neglect of investment control”, and “emphasis on technical aspects of supervision and neglect of economic aspects of supervision”. In reality, rights of supervision tend to be confined to management of technical aspects, while management of economic aspects is firmly in control of proprietors. Meanwhile, lagging behind of existing construction cost management system is the primary cause for losing control of construction cost. Therefore, as a whole, the phenomenon of losing control over construction project cost is still quite serious, so it is necessary to conduct further study and make further analysis on major factors of current construction cost management and factors at all stages of a construction project that affect construction cost.2. Primary study contentAiming at the subject of “control of whole-process of construction project cost”, and based on lots of literature reviews about determination and control of construction project cost both at home and abroad, the author of this paper has collected extensively some relevant provincial and city reports and data after investigation. Afterwards, the author conducts the following work.1) To analyze formulation of construction project investment and to find out primary reasons for losing control over construction cost at all stages of a construction project.2) To study and analyze status quo and existing issues of current construction cost management, and study influences of these issues upon determination and control of a construction cost.3) To put forward effective approaches and methods as well application of value engineering of a construction project from its decision-making stage, design stage, construction stage to the final acceptance of construction stage.1454) To make clear significance, necessity and feasibility of cost control of a construction project so as to provide recommendations for improvement of construction cost management in China.2.1 Construction cost control theory and management mod eAccording to the new cost control theory, cost engineers are “professional persons who undertake cost estimate, cost control, marketing planning and scientific management”. Fields undertaken by cost engineers include such aspects as project management, project planning, progress management and profitability analysis etc of a project construction and its production process. Cost engineers offer service for control over life cycle expenditure, property facilities and production & manufacture of a construction project with their management technique with an overall cost.2.2 Current construction cost management model and theories in China2.2.1 Direct regulation and control of the governmentConsidering development process of quota, it can be discovered that quota has come into being, developed and become mature gradually with development of planned economy after foundation of PRC. Since China has carried out centralized management model of investment system for a long time, the government is not only a maker of macropolicy, but a participant of micro-project construction. Therefore, a unified quota with dense colour of planned economy is able to provide powerful methods and means for the government to carry out macro-investment regulation and control and micro-construction project management.2.2.2 Valuation basis for current construction costBasic materials for calculation of construction cost usually include construction cost quota, construction cost expense quota, cost index, basic unit price, quantities calculation rule and relevant economic rules and policies issued by competent departments of the government, etc. It includes index of estimate (budgetary estimate index), budgetary estimate quota, budgetary quota (comprehensive budgetary quota), expense quota (standard), labor quota, working-day norm, materials, budgetary price of facilities, direct price index of a project, material price index and cost index. And also included is valuation criterion of consumption quota and list of items in recent two years.2.2.3 Valuation model of current construction costValuation model is a basic aspect of construction cost management. Construction cost management is a governmental behavior, while valuation model is a means for a country to manage and control construction cost. There are two construction valuation models at present in China, namely, valuation model according to quota and one according to bill of quantities.2.2.3.1 Valuation model according to quotaValuation model according to quota is an effective model adopted during the transition period from planned economy to market economy. Determination of construction cost through valuation model according to quota prevents overrated valuation and standards and prices pressed down to some extent, because budgetary quota standardizes rate of consumption and a variety of documents stipulate manpower, materials, unit price of machines and all sorts of service fee norms, which reflects normativity, unitarity and rationality of construction cost. However, it has an inhibited effect upon market competition, and is not favorable for a construction enterprise to improve its technique, strengthen its management and enhance its labor efficiency and market competition.2.2.3.2 Valuation model according to bill of quantitiesValuation model according to bill of quantities is a construction cost determination model proposed recently. In this model, the government merely unifies project code, project name, unit of measurement and measurement rule of quantities. Each construction enterprise has its self-determination to quote a price according to its own situation in a tender offer, and price of building products is formed thereby in the process of bidding.2.3 Cost control in the process of implementationFor a long time, technique and economy has been separated in the field of project construction. Restrained by the planned economy, there lacks the economic concept in the minds of our engineers and technicians, because they regard reduction of construction cost as a duty of financial personnel which has nothing to do with themselves. However, the primary responsibility of financial and preliminary budget personnel is to act in accordance with financial system. Usually, they are not familiar with construction technique, and know little or even nothing about changes of various relations in project design, construction content and implementation of construction. Under such a circumstance, they have no choice but to mechanically work out or audit the expenditure from a financial perspective, which results in mutual separation of technique and economy. They just do what they do, which negatively reflects price of quantities of a project that has been completed, so it is difficult to control construction cost rationally and effectively.1462.4 Control of cost in the process of constructionImplementation stage of a construction project is a stage which requires the most assets in the whole process of a project construction, and is also a vital stage for pecuniary resources to transform into building entities. Cost control at the implementation stage refers to confine construction cost within a scheduled control scope through a scientific cost control theory and method on the condition of ensuring project quality and time limit. The process of generation of a building entity is inreversible, so if effective automatic control and precontrol cannot be conducted over construction cost, then economic loss might be caused that cannot be made up for.2.5 Analysis of major factors that affect construction cost at the stage of implementationImplementation stage of a project refers to the period from completion of construction documents design and examination and submission to the construction party to the final completion acceptance of the project and until it is put into use. According to the basic operation procedure of the implementation stage of a construction project, formation of a construction cost has to undergo such major aspects as bidding, contract signing and management, joint auditing of a shop drawing, investigation of a construction management plan, material management and completion settlement, etc. All these aspects affect construction cost settlement to different degrees. In that process, after evolving from budgetary price, price for successful bidding, refurbishing cost for a contract, the construction cost is finally determined in the form of settlement price for project completion. Factors affecting construction cost are various, but from the perspective of analysis of cost formation, there are primarily the following reasons.1) Influences of a project bidding. Bidding can determine price for successful bidding, while contract price is determined on the basis of price for successful bidding. If something goes wrong with bidding, then it might result in distortion of the price for bidding, and it is impossible to provide accurate and reliable foundation for cost control, and even result in losing control over the cost.2) Influences of contract signing and management. Determination of a contract price further makes precise target of cost control, and an initial draft of a contract term provides correct foundation and principles for cost control. After signing of a contract, contract items are regarded as foundation, which will have strict contract control over design changes at the construction stage, project measurement, payment of a construction debt, and construction compensation, etc, and which will ensure realization of a control target. Therefore, losing control over signing and management of a contract will necessarily result in losing control over construction cost.3) Influences of examination of construction management plan. Construction management plan is one of important foundations for determine a project bidding price and contract price. In the process of construction, adjustment of a contract price should also be determined according to construction management plan, because quality of construction management plan will directly affect quality and progress of a project. Therefore, losing control over examination of construction management plan will bring extremely unfavorable influences upon control over construction cost.4) Influences of material management. On one hand, material price is an important component of bidding price and contract price. On the other hand, material expense accounts for a large proportion in construction cost, because price of materials determine construction cost. Therefore, losing control over material management will necessarily result in losing control over construction cost.5) Influences of settlement, examination and verification of a project completion. Settlement, examination and verification is the final stage of a construction cost control at the implementation stage. A strict and meticulous settlement, examination and verification can ensure accuracy and authenticity of settlement cost of a project. According to previous analysis, we believe that all aspects of cost control can have effect upon formation of construction cost, among which bidding of a project, contract signing and management, examination of a construction management plan and management of materials all have decisive effects upon formation of construction cost, and are vital aspects in cost construction at the implementation stage of a project, so neglect of these four aspects is a direct cause for losing control over construction cost.In this paper, the author summarizes relevant issues in construction cost control at the decision-making stage of a construction project, at the design stage and construction stage, and puts forward principles or resolutions for handing such issues. Especially, as a method of combination of technique and economics, application of value engineering is elaborated at all stages, so that construction cost gets effective controlled. 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Project Management in Construction.Stephen P Robbins & David A. Decenzo. (2002). Fundament of Management. Prentice Hall, Inc.148Takashi Ishikawa. (1996). Analogy by Abstraction: Case Retrieval and Adaptation for Inventive Design Expert Systems. Expert Systems with Application, (4)10.Tao, Xueming, Huang, Yunde & Xiong, Wei. (2004). Construction Cost Valuation and Management. China Architecture & Building Press, 2.Wang, Ailin. (2003). Value Engineering and Its Application in Constructional Engineering. Anhui Architecture, (5). Wang, Li & Xu, Zihua. (2004). Comparative Study on Construction Cost Models at Home and Abroad. Architecture Economics.Wang, Yulong. (1997). 2000 Cases on Issues of Construction Project Cost. Shanghai: Tongji University Press. Wang, Zhenqiang. (2002). British Construction Cost Management. Tianjin: Nankai University Press.Wang, Zhenqiang. (2002). Japanese Construction Cost Management. Tianjin: Nankai University Press, 4.Xiang, Ke & Luo, Feng. (2004). Cost Control of Design Stage. Sichuan Architecture, (2).Xu, Datu. (1997). Determination and Control of Construction Cost. Beijing: China Planning Press.Xu, Datu. (1997). Investment Control of Construction Project. Beijing: China Planning Press.Yin, Yilin. (2001). Determination and Control of Construction Cost. Beijing: China Planning Press.Zhang, Caijiang, Li, Kehua & Xu, Yongmei. Review of VE Theory and Practice in China and Some Deep Thinking about its Depression. Nankai Business Review, (1).Zhong, Guangen. (2004). Brief Discussion on Cost Control System in Projects of Commonwealth Nations.Zuo, Jin & Han, Hongyun. Actuality & Amelioration of Whole Life-cycle Value-chain in Architecture. Value Engineering, (6).149。

土木工程-毕业设计-论文-外文翻译-中英文对照

英文原文：Concrete structure reinforcement designSheyanb oⅠWangchenji aⅡⅠFoundation Engineering Co., Ltd. Heilongjiang DongyuⅡHeilongjiang Province, East Building Foundation Engineering Co., Ltd. CoalAbstract：structure in the long-term natural environment and under the use environment's function, its function is weaken inevitably gradually, our structural engineering's duty not just must finish the building earlier period the project work, but must be able the science appraisal structure damage objective law and the degree, and adopts the effective method guarantee structure the security use, that the structure reinforcement will become an important work. What may foresee will be the 21st century, the human building also by the concrete structure, the steel structure, the bricking-up structure and so on primarily, the present stage I will think us in the structure reinforcement this aspect research should also take this as the main breakthrough direction.Key word：Concrete structure reinforcement bricking-up structure reinforcement steel structure reinforcement1 Concrete structure reinforcementConcrete structure's reinforcement divides into the direct reinforcement and reinforces two kinds indirectly, when the design may act according to the actual condition and the operation requirements choice being suitable method and the necessary technology.1.1the direct reinforcement's general method1）Enlarges the section reinforcement lawAdds the concretes cast-in-place level in the reinforced concrete member in bending compression zone, may increase the section effective height, the expansion cross sectional area, thus enhances the component right section anti-curved, the oblique section anti-cuts ability and the section rigidity, plays the reinforcement reinforcement the role.In the suitable muscle scope, the concretes change curved the component right section supporting capacity increase along with the area of reinforcement and the intensity enhance. In the original component right section ratio of reinforcement not too high situation, increases the main reinforcement area to be possible to propose the plateau component right section anti-curved supporting capacity effectively. Is pulled in the section the area to add the cast-in-place concrete jacket to increase the component section, through new Canada partial and original component joint work, but enhances the component supporting capacity effectively, improvement normal operational performance.Enlarges the section reinforcement law construction craft simply, compatible, and has the mature design and the construction experience; Is suitable in Liang, the board, the column, the wall and the general structure concretes reinforcement; But scene construction's wet operating time is long, to produces has certain influence with the life, and after reinforcing the building clearance has certain reduction.2) Replacement concretes reinforcement lawThis law's merit with enlarges the method of sections to be close, and after reinforcing, does not affect building's clearance, but similar existence construction wet operating time long shortcoming; Is suitable somewhat low or has concretes carrier's and so on serious defect Liang, column in the compression zone concretes intensity reinforcement.3) the caking outsourcing section reinforcement lawOutside the Baotou Steel Factory reinforcement is wraps in the section or the steel plate is reinforced component's outside, outside the Baotou Steel Factory reinforces reinforced concrete Liang to use the wet outsourcing law generally, namely uses the epoxy resinification to be in the milk and so on methods with to reinforce the section the construction commission to cake a whole, after the reinforcement component, because is pulled with the compressed steel cross sectional area large scale enhancement, therefore right section supporting capacity and section rigidity large scale enhancement.This law also said that the wet outside Baotou Steel Factory reinforcement law, the stress is reliable, the construction is simple, the scene work load is small, but is big with the steel quantity, and uses in above not suitably 600C in the non-protection's situation the high temperature place; Is suitable does not allow in the use obviously to increase the original component section size, but requests to sharpen its bearing capacity large scale the concrete structure reinforcement.4) Sticks the steel reinforcement lawOutside the reinforced concrete member in bending sticks the steel reinforcement is (right section is pulled in the component supporting capacity insufficient sector area, right section compression zone or oblique section) the superficial glue steel plate, like this may enhance is reinforced component's supporting capacity, and constructs conveniently.This law construction is fast, the scene not wet work or only has the plastering and so on few wet works, to produces is small with the life influence, and after reinforcing, is not remarkable to the original structure outward appearance and the original clearance affects, but the reinforcement effect is decided to a great extent by the gummy craft and the operational level; Is suitable in the withstanding static function, and is in the normal humidity environment to bend or the tension member reinforcement.5) Glue fibre reinforcement plastic reinforcement lawOutside pastes the textile fiber reinforcement is pastes with the cementing material the fibre reinforcement compound materials in is reinforced the component to pull the region, causes it with to reinforce the section joint work, achieves sharpens the component bearing capacity the goal. Besides has glues the steel plate similar merit, but also has anticorrosive muddy, bears moistly, does not increase the self-weight of structure nearly, durably, the maintenance cost low status merit, but needs special fire protection processing, is suitable in each kind of stress nature concrete structure component and the general construction.This law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.6) Reeling lawThis law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.7) Fang bolt anchor lawThis law is suitable in the concretes intensity rank is the C20~C60 concretes load-bearing member transformation, the reinforcement; It is not suitable for already the above structure which and the light quality structure makes decent seriously. 1.2The indirect reinforcement's general method1)Pre-stressed reinforcement law(1)Thepre-stressed horizontal tension bar reinforces concretes member in bending,because the pre-stressed and increases the exterior load the combined action, in the tension bar has the axial tension, this strength eccentric transmits on the component through the pole end anchor (, when tension bar and Liang board bottom surface close fitting, tension bar can look for tune together with component, this fashion has partial pressures to transmit directly for component bottom surface), has the eccentric compression function in the component, this function has overcome the bending moment which outside the part the load produces, reduced outside the load effect, thus sharpened component's anti-curved ability. At the same time, because the tension bar passes to component's pressure function, the component crack development can alleviate, the control, the oblique section anti-to cut the supporting capacity also along with it enhancement.As a result of the horizontal lifting stem's function, the original component's section stress characteristic by received bends turned the eccentric compression, therefore, after the reinforcement, component's supporting capacity was mainly decided in bends under the condition the original component's supporting capacity 。

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。

土木工程外文文献翻译(含中英文)

Experimental research on seismic behavior of abnormal jointin reinforced concrete frameAbstract :Based on nine plane abnormal joint s , one space abnormal joint experiment and a p seudo dynamic test of a powerplant model , the work mechanism and the hysteretic characteristic of abnormal joint are put to analysis in this paper. A conception of minor core determined by the small beam and small column , and a conclusion that the shear capacity of ab2normal joint depends on minor core are put forward in this paper. This paper also analyzes the effect s of axial compres2 sion , horizontal stirrup s and section variation of beam and column on the shear behavior of abnormal joint . Finally , the formula of shear capacity for abnormal joint in reinforced concrete f rame is provided.Key words : abnormal j oint ; minor core ; seismic behavior ; shear ca paci t yCLC number :TU375. 4 ; TU317. 1 Document code :A Article ID :100627930 (2006) 022*******1 Int roductionFor reinforced concrete f rame st ructure , t he joint is a key component . It is subjected to axialcomp ression , bending moment and shear force. The key is whet her the joint has enough shear capaci2ty. The Chinese Code f or S eismic Desi gn of B ui l di ngs ( GB5001122001) adopt s the following formulato calculate t he shear capacity of the reinforced concrete f rame joint .V j = 1. 1ηj f t b j h j + 0. 05ηj Nb jb c+ f yv A svjh b0 - a′ss(1)Where V j = design value of t he seismic shear capacity of the joint core section ;ηj = influential coefficient of t he orthogonal beam to the column ;f t = design value of concrete tensile st rength ;b j = effective widt h of the joint core section ;h j = dept h of the joint core section , Which can be adopted as t he depth of the column section int he verification direction ;N = design value of axial compression at t he bot tom of upper column wit h considering the combi2 nation of the eart hquake action , When N > 015 f c b c h c , let N = 0. 5 f c b c h c ;b c = widt h of t he column section ;f yv = design value of t he stirrup tensile st rengt h ;A svj = total stirrup area in a set making up one layer ;h b0 = effective dept h of t he beam.If t he dept h of two beams at the side of t he joint is unequal , h b0 = t he average depth of two beams.a′s = distance f rom the cent roid of the compression beam steel bar to the ext reme concrete fiber . s = distance of t he stirrup .Eq. 1 is based on t he formula in t he previous seismiccode[1 ] and some modifications made eavlicr and it is suit2able to the normal joint of reinforced concrete f rame , butnot to t he abnormal one which has large different in t hesection of t he upper column and lower one (3 600 mm and1 200 mm) , lef t beam and right beam (1 800 mm and 1200 mm) . The shear capacity of abnormal joint s calculat2ed by Eq. 1 may cause some unsafe result s. A type of ab2normal joint which of ten exist s in t he power plant st ruc2t ure is discussed ( see Fig. 1) , and it s behavior was st ud2ied based on t he experiment in t his paper2 Experimental workAccording to the above problem , and t he experiment of plane abnormal joint s and space abnormal joint , a p seudo dynamic test of space model of power plant st ruct ure was carried out . The aim of t hisst udy is to set up a shear force formula and to discuss seismic behavior s of t he joint s.According to the characteristic of t he power plant st ruct ure , nine abnormal joint s and one space abnormal joint were designed in t he experiment . The scale of the model s is one2fif t h. Tab. 1 and Tab.2 show t he dimensions and reinforcement detail s of t he specimens.Fig. 2 shows the typical const ruction drawing of t he specimen. Fig. 3 shows the loading set up . These specimens are subjected to low2cyclic loading , the loading process of which is cont rolled by force and displacement , t he preceding yield loading by force and subsequent yield by t he displacement .The shear deformation of the joint core , t he st rain of the longit udinal steel and t he stirrup are main measuring items.3 Analysis of test result s3. 1 Main resultsTab. 3 shows t he main result s of t he experiment .3. 2 Failure process of specimenBased on t he experiment , t he process of t he specimens’failure includes four stages , namely , t he initial cracking , t he t horough cracking , the ultimate stage and t he failure stage.(1) Initial cracking stageWhen t he first diagonal crack appears along t he diagonal direction in t he core af ter loading , it s widt h is about 0. 1mm , which is named initial cracking stage of joint core. Before t he initial cracking stage , t he joint remains elastic performance , and the variety of stiff ness is not very obvious on t hep2Δcurve. At t his stage concrete bear s most of the core shear force while stirrup bears few. At t he timewhen t he initial crack occur s , t he st ress of t he stirrup at t he crack increase sharply and t he st rain is a2bout 200 ×10 - 6 —300 ×10 - 6 . The shear deformation of t he core at t his stage is very small (less than 1×10 - 3 radian ,generally between 0. 4 ×10 - 3 and 0. 8 ×10 - 3 radian) .(2) Thorough cracking stageWit h the load increasing following t he initial cracking stage , the second and t hird crossing diago2 nal cracks will appear at t he core. The core is cut into some small rhombus pieces which will become at least one main inclined crack across t he core diagonal . The widt h of cracks enlarges obviously , andt he wider ones are generally about 0. 5mm , which is named core t horough cracking stage. The st ress of stirrup increases obviously , and the stirrup in t he middle of t he core is near to yielding or has yiel2 ded. The joint core shows nonlinear property on t he p2Δcurve , and it enter s elastic2plastic stage. Theload at t horough cracking stage is about 80 % —90 % load.(3) Ultimate stageAt t his stage , t he widt h of t he cracks is about 1mm or more and some new cracks continue to oc2 cur . The shear deformation at t he core is much larger and concrete begins to collap se. Af ter several cyclic loading , the force reaches the maximum value , which is called ultimate stage. The load increase is due to t he enhancing of the concrete aggregate mechanical f riction between cracks. At t he same timet he st ress of stirrup increases gradually. On t he one hand stirrup resist s t he horizontal shear , and on t he ot her hand the confinement effect to t he expanding compression concrete st rengthens continuous2ly , which can also improve t he shear capacity of diagonal compression bar mechanism.(4) Failure stageAs the load circulated , concrete in t he core began to collap se , and t he deformation increased sharply , while the capacity began to drop . It was found t hat t he slip of reinforcement in t he beam wasvery serious in t he experiment . Wit h t he load and it s circulation time increasing , t he zoon wit houtbond gradually permeated towards t he internal core , enhancing t he burden of t he diagonal compressionbar mechanism and accelerates the compression failure of concrete. Fig. 4 shows t he p hotos of typical damaged joint s.A p seudo dynamic test of space model ofpower plant st ruct ure was carried out to researcht he working behavior of t he abnormal joint s in re2al st ructure and the seismic behavior of st ructure.Fig. 5 shows the p hoto of model .The test includes two step s. The fir st is thep seudo dynamic test . At t his step , El2Cent rowave is inp ut and the peak acceleration variesf rom 50 gal to 1 200 gal . The seismic response is measured. The second is t he p seudo static test . Theloading can’t stop until t he model fail s.Fig. 7 Minor coreThe experiment shows t hat t he dist ribution and development of t hecrack is influenced by t he rest rictive effect of the ort hogonal beam , andt he crack of joint core mainly dist ributes under t he orthogonal beam( see Fig. 6) , which is different f rom t he result of t he plane joint test ,but similar to J 4210.3. 3 Analysis of test results3. 3. 1 Mechanical analysisIn t he experiment , t he location of the initial crack of t he exteriorjoint and the crushed position of concrete both appear in the middle oft he joint core , and t he position is near t he centerline of t he upper col2umn. The initial crack and crushed position of t he concrete of the interior joint both appear in t he mi2 nor core ( see Fig. 4 ,Fig. 7) . For interior abnormal joint t he crack doesn’t appear or develop in t he ma2j or core out side of the mi nor core until t horough cracking takes place , while t he crack seldom appearsin t he shadow region ( see Fig. 7) as the joint fail s. Therefore , for abnormal joint , t he shear capacity oft he joint core depends on t he properties of t he mi nor core , namely , on t he st rengt h grades of concrete ,t he size and the reinforcement of t he mi nor core , get t he effect of t he maj or core dimension can’t be neglected.Mechanical effect s are t he same will that of t he normal joint , when t he forces t ransfer to t he mi2 nor core t hrough column and beam and reinforcement bar . Therefore , t he working mechanisms of nor2mal joint , including t russ mechanism , diagonal compression bar mechanism and rest rictive mechanismof stirrup , are also suitable for mi nor core of t he abnormal joint , but their working characteristic is not symmet rical when the load rever ses. Fig. 8 illust rates t he working mechanism of t he abnormal joint .When t he load t ransfer to mi nor core , t he diagonal compression bar area of mi nor core is biggert han normal joint core2composed by small column and small beam of abnormal joint , which is due to t he compressive st ress diff usion of concrete compressive region of the beam and column , while at t hesame time t he compression carried by the diagonal compression bar becomes large. Because t he main part of bond force of column and beam is added to t he diagonal comp ression bar but cont rasting wit h t he increased area of diagonal compression bar , t he increased action is small . The region in the maj orcore but out of the mi nor core has less st ress dist ribution and fewer cracks. The region can confine t heexpansion of t he concrete of t he mi nor core diagonal compression bar concrete , which enhances t he concrete compressive st rengt h of mi nor core diagonal compression bar .Making t he mi nor core as st udy element , the area increment of concrete diagonal compression barin mi nor core is related to t he st ress diff usion of t he beam and column compressive region. The magni2t ude of diff usion area is related to height difference of t he beam sections and column sections. Name2ly , it is related to t he size of mi nor core section and maj or core section. Thus , the increased shearst rengt h magnit ude caused by mi nor core rest rictive effect on maj or core can be measured quantitative2ly by t he ratio of maj or core area to mi nor core area. And it al so can be expressed that t he rest rictive effect is quantitatively related to t he ratio. Obviously , t he bigger t he ratio is and t he st ronger t he con2finement is , t he st ronger t he bearing capacity is.The region in the maj or core but under the mi nor core still need stirrup bar because of t he hori2 zontal force t ransferred by bigger beam bar . But force is small .3. 3. 2 load2displacement curves analysisFig. 9 shows t he typical load2displacement curves at t he beam end of t he exterior and interiorjoint . The figure showing t hat t he rigidity of t he specimens almo st doesn’t degenerate when t he initialcrack appear s in t he core , and a turning point can be found at t he curve but it isn’t very obvious. Wit ht he crack developing , an obvious t urning point can be found at t he curve , and at t his time , t he speci2men yields. Then t he load can increase f urt her , but it can’t increase too much f rom yielding load to ultimate load. When t he concrete at t he core collap ses and the plastic hinge occured at t he beamend ,t he load begins to decrease rat her t han increase.The ductility coefficient of two kinds of joint s is basically more than 3 (except for J 3 - 9) . But it should be noted t hat the design of specimens is based on the principle of joint core failure. The ratio of reinforcement of beam and column tends to be lower t han practical project s. If t he ratio is larger , t he failure of joint is probably prior to t hat of beam and column , so t he hysteretic curve reflect s t he ductil ity property of joint core.Joint experiment should be a subst ruct ure test (or a test of composite body of beams and col2 umns) . So t he load2displacement curves at t he beam end should be a general reflection of t he joint be2havior work as a subst ruct ure. Providing t hat the joint core fails af ter t he yield of beam and column (especially for beam) , t he load2displacement curves at t he beam end is plump , so the principle of “st rong col umn and weak beam , st ron ger j oi nt" should be ensured which conforms to t he seismic re2sistant principle.The experiment shows t hat t he stiff ness of joint core is large. Before the joint reaches ultimatestage , t he stiff ness of joint core decreases a little and the irrecoverable residual deformation is very small under alternate loading. When joint core enter s failure stage , t he shear deformation increases sharply , and t he stiff ness of joint core decreases obviously , and t he hysteretic curve appears shrink2 age , which is because of t he cohesive slip of beam reinforcement .3. 4 Influential Factors of Abnormal Joint Shear CapacityThe fir st factor is axial compression. Axial compression can enlarge t he compression area of col2 umn , and increase t he concrete compression area of joint core[124 ] . At t he same time , more shearst ransferred f rom beam steel to t he edge of joint core concrete will add to t he diagonal compression bar ,which decreases t he edge shear t hat leads to the crack of joint core concrete. So t he existence of axial comp ression cont ributes to imp roving t he capacity of initial cracks at joint core.The effect of axial compression on t horough cracking load and ultimate load isn’t very obvious[1 ] . The reason is t hat cont rasting wit h no axial compression , the accumulated damage effect of joint coreunder rever sed loading wit h axial compression is larger . Alt hough axial compression can improve t heshear st rengt h of concrete , it increases accumulated damage effect which leads to a decrease of the ad2vantage of axial compression. Therefore t he effect of axial compression on t horough cracking loadandultimate load is not very obvious.Hence , considering the lack of test data of abnormal joint , t he shear capacity formula of abnormal joint adopt 0. 05 nf c b j h j to calculate the effect of axial compression , which is based on the result s of t his experiment and referenced to t he experimental st udy and statistical analysis of Meinheit and J irsa ,et [5 ] .The second factor is horizontal stirrup . Horizontal stirrup has no effect on t he initial crackingshear of abnormal joint , while greatly improves t he t horough cracking shear . Af ter crack appeared , t he stirrup begins to resist t he shear and confines t he expansion of concrete[ 6 ] . This experiment showst hat t he st ress of stirrup s in each layer is not equal . When the joint fail s , t he stirrup s don’t yield simultaneous. Fig. 10 shows t he change of st ress dist ribution of stirrup s along core height wit h t he loadincreasing. Through analyzing test result s , it can be known t hat 80 percent of the height at the joint core can yield.The last factor is the change of sec2tion size of t he beam and column. Thesection change decreases t he initial crack2ing load about 30 p resent of abnormaljoint and makes t he initial crack appear att he position of joint mi nor core. The rea2son for t his p henomenon is t hat small up2per column section makes t he confinementof mi nor core concrete decrease and t heedge shear increase. But t he section change has lit tle effect on thorough cracking load. Af ter t horoughcracking , the joint enter s ultimate state while the external load can’t increase too much , which is dif2 ferent f rom t he behavior of abnormal joint t hat can carry much shear af ter thorough cracking.3. 5 Shear force formula of abnormal jointAs a part of f rame , t he design of joint shall meet t he requirement s of the f rame st ruct ure design , namely , t he joint design should not damage t he basic performance of t he st ruct ure.According to the principle of st ronger j oi nt , it is necessary for joint to have some safety reserva2 tion. The raised cost for conservational estimation of t he joint bearing capacity is small . But t he con2 servational estimation is very important to t he safety of the f rame st ruct ure. At t horough cracking stage , t he widt h of most cracks is more t han 0. 2 mm , which is bigger than t he suggested limit value in t he concrete design code. Big cracks will influence t he durability of st ruct ure. Hence , the bearing capacity at t horough cracking stage is applied to calculating t he bearing capacity of joint . According to t he analysis of t he working mechanisms of abnormal joint , it could be concludedt hat t he bearing capacity of joint core mainly depends on mi nor core when t he force t ransferred f rommaj or core to mi nor core. All kinds of working mechanisms are suitable to mi nor core element . Thus , a formula for calculating t he shear capacity of abnormal joint can be obtained based on Eq. 1. According to the above analysis of influential factor s of shear capacity of abnormal joint , and ref2 erence to Eq. 1 , a formula for calculating t he shear capacity of reinforced concrete f rame abnormal jointis suggested as followsV j = 0. 1ηjξ1 f c b j h j + 0. 1ηj nξ2 f c b j h j +ξ3 f yv A svj h0 - a′s s(2)Where h0 = effective dept h of small beam section in abnormal joint ;ξ1 = influential coefficient consider2ing mi nor core on working as cont rol element for calculating ;ξ2 = influential coefficient considering effect of axial compression ratio , it s value is 0. 5 , andξ3 = influential coefficient considering t hestir2rup doesn’t yield simultaneous , it s value is 0. 8 , n = N/ f c b c h j .From Fig. 8 , the shear capacity of abnormal joint depends on mi nor core , while maj or core has re2st rictive effect on mi nor core. The effect is related to t he ratio of maj or core area to mi nor core area , so assumingξ1 =αA d A x (3)Where A d = area of abnormal joint maj or core , choosing it as t he value of t he dept h of big beam multiplying t he height of lower column ; A x = area of abnormal joint mi nor core , choosing it as t he value oft he depth of small beam multiplying the height of upper column ; andα= parameter to be defined , it s value is 0. 8 derived f rom t he result s of t he experiment ( see Tab. 4)Then Eq. 2 can be replaced byV j = 0. 1ηjαA d A x f c b j h j + 0. 05ηj n f c b j h j + 0. 8 f yv h0 - a′s s(4)4 ConclusionsThe following conclusions can be drawn f rom t his study.(1) The seismic behavior of abnormal joint in reinforced concrete f rame st ruct ure is poor . Af tert horough cracking , t he joint enter s ultimate state while the external load can’t increase too much , andt he safety reservation of joint isn’t sufficient .(2) The characteristic of bearing load of minor core is similar to that of normal joint , but t he area bearing load is different . The shear capacity depend on t he size , t he st rengt h of concrete and the rein2forcement of mi nor core in abnormal joint . The maj or core has rest rictive effect on mi nor core. (3) Joint experiment should be a subst ruct ure test or a test of composite body of beams and col2 umns. Therefore t he load2displacement curves of t he beam end should be a general reflection of t he joint behavior working as a subst ruct ure. Studies of t he hysteretic curve of subst ruct ure should be based on t he whole st ructure. It is critical to guarantee t he stiff ness and st rengt h of joint core in prac2tice.(4) The formula of shear capacity for abnormal joint in reinforced concrete f rame is provided.References[1 ] TAN GJ iu2ru . The seismic behavior of steel reinforced concrete f rame [M] . Nanjing :Dongnan University Press ,1989 :1572163.[2 ] The research group of reinforcement concrete f rame joint . Shear capacity research of reinforced concrete f rame jointon reversed2cyclic loading[J ] . Journal of Building St ructures , 1983 , (6) :9215.[3 ] PAULA Y T ,PARK R. Joint s reinforced concrete f rames designed for earthquake resistance[ R] . New Zealand :De2partment of civil Engineering , University of Canterbury , Christchurch , 1984.[4 ] FU Jian2ping. Seismic behavior research of reinforced concrete f rame joint with the consideration of axialforce[J ] .Journal of Chongqing Univ , 2000 , (5) :23227.[5 ] MEINHEIT D F ,J IRSA J O. Shear st rength of R/ C beam2column connections [J ] . ACI St ructural Journal , 1993 ,(3) :61271.[6 ] KITA YAMA K, OTANI S ,AO YAMA H. Development of design criteria for RC interior beam2column joints ,de2sign of beam2column joint s for seismic resistance[ R] . SP123 ,ACI ,Det roit , 1991 :61272.[7 ] GB5001122001 ,Code for seismic design of buildings [ S] . Beijing : China Architectural and BuildingPress ,2001.钢筋混凝土框架异型节点抗震性能试验研究摘要：基于8个钢筋混凝土框架异型节点的试验研究，分析了异型框架节点的受力与常规框架节点的异同。

土木工程专业毕业设计外文文献翻译2篇

XXXXXXXXX学院学士学位毕业设计（论文）英语翻译课题名称英语翻译学号学生专业、年级所在院系指导教师选题时间Fundamental Assumptions for Reinforced ConcreteBehaviorThe chief task of the structural engineer is the design of structures. Design is the determination of the general shape and all specific dimensions of a particular structure so that it will perform the function for which it is created and will safely withstand the influences that will act on it throughout useful life. These influences are primarily the loads and other forces to which it will be subjected, as well as other detrimental agents, such as temperature fluctuations, foundation settlements, and corrosive influences, Structural mechanics is one of the main tools in this process of design. As here understood, it is the body of scientific knowledge that permits one to predict with a good degree of certainly how a structure of give shape and dimensions will behave when acted upon by known forces or other mechanical influences. The chief items of behavior that are of practical interest are (1) the strength of the structure, i. e. , that magnitude of loads of a give distribution which will cause the structure to fail, and (2) the deformations, such as deflections and extent of cracking, that the structure will undergo when loaded under service condition.The fundamental propositions on which the mechanics of reinforced concrete is based are as follows:1.The internal forces, such as bending moments, shear forces, and normal andshear stresses, at any section of a member are in equilibrium with the effect of the external loads at that section. This proposition is not an assumption but a fact, because any body or any portion thereof can be at rest only if all forces acting on it are in equilibrium.2.The strain in an embedded reinforcing bar is the same as that of thesurrounding concrete. Expressed differently, it is assumed that perfect bonding exists between concrete and steel at the interface, so that no slip can occur between the two materials. Hence, as the one deforms, so must the other. With modern deformed bars, a high degree of mechanical interlocking is provided in addition to the natural surface adhesion, so this assumption is very close to correct.3.Cross sections that were plane prior to loading continue to be plan in themember under load. Accurate measurements have shown that when a reinforced concrete member is loaded close to failure, this assumption is not absolutely accurate. However, the deviations are usually minor.4.In view of the fact the tensile strength of concrete is only a small fraction ofits compressive strength; the concrete in that part of a member which is in tension is usually cracked. While these cracks, in well-designed members, are generally so sorrow as to be hardly visible, they evidently render the cracked concrete incapable of resisting tension stress whatever. This assumption is evidently a simplification of the actual situation because, in fact, concrete prior to cracking, as well as the concrete located between cracks, does resist tension stresses of small magnitude. Later in discussions of the resistance of reinforced concrete beams to shear, it will become apparent that under certain conditions this particular assumption is dispensed with and advantage is taken of the modest tensile strength that concrete can develop.5.The theory is based on the actual stress-strain relation ships and strengthproperties of the two constituent materials or some reasonable equivalent simplifications thereof. The fact that novelistic behavior is reflected in modern theory, that concrete is assumed to be ineffective in tension, and that the joint action of the two materials is taken into consideration results in analytical methods which are considerably more complex and also more challenging, than those that are adequate for members made of a single, substantially elastic material.These five assumptions permit one to predict by calculation the performance of reinforced concrete members only for some simple situations. Actually, the joint action of two materials as dissimilar and complicated as concrete and steel is so complex that it has not yet lent itself to purely analytical treatment. For this reason, methods of design and analysis, while using these assumptions, are very largely based on the results of extensive and continuing experimental research. They are modified and improved as additional test evidence becomes available.钢筋混凝土的基本假设作为结构工程师的主要任务是结构设计。

土木工程文献外文翻译(中英互译版)

使用加固纤维聚合物增强混凝土梁的延性作者：Nabil F. Grace, George Abel-Sayed, Wael F. Ragheb摘要：一种为加强结构延性的新型单轴柔软加强质地的聚合物(FRP)已在被研究，开发和生产(在结构测试的中心在劳伦斯技术大学)。

这种织物是两种碳纤维和一种玻璃纤维的混合物，而且经过设计它们在受拉屈服时应变值较低，从而体现出伪延性的性能。

通过对八根混凝土梁在弯曲荷载作用下的加固和检测对研制中的织物的效果和延性进行了研究。

用现在常用的单向碳纤维薄片、织物和板进行加固的相似梁也进行了检测，以便同用研制中的织物加固梁进行性能上的比较。

这种织物经过设计具有和加固梁中的钢筋同时屈服的潜力，从而和未加固梁一样，它也能得到屈服台阶。

相对于那些用现在常用的碳纤维加固体系进行加固的梁，这种研制中的织物加固的梁承受更高的屈服荷载，并且有更高的延性指标。

这种研制中的织物对加固机制体现出更大的贡献。

关键词：混凝土，延性，纤维加固，变形介绍外贴粘合纤维增强聚合物（FRP）片和条带近来已经被确定是一种对钢筋混凝土结构进行修复和加固的有效手段。

关于应用外贴粘合FRP板、薄片和织物对混凝土梁进行变形加固的钢筋混凝土梁的性能，一些试验研究调查已经进行过报告。

Saadatmanesh和Ehsani（1991）检测了应用玻璃纤维增强聚合物(GFRP)板进行变形加固的钢筋混凝土梁的性能。

Ritchie等人（1991）检测了应用GFRP，碳纤维增强聚合物（CFRP）和G/CFRP板进行变形加固的钢筋混凝土梁的性能。

Grace等人（1999）和Triantafillou（1992）研究了应用CFRP薄片进行变形加固的钢筋混凝土梁的性能。

Norris，Saadatmanesh和Ehsani（1997）研究了应用单向CFRP薄片和CFRP织物进行加固的混凝土梁的性能。

在所有的这些研究中，加固的梁比未加固的梁承受更高的极限荷载。

(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。

土木工程毕业论文中英文翻译

外文翻译班级：xxx学号：xxx姓名：xxx一、外文原文：Structural Systems to resist lateral loads Commonly Used structural SystemsWith loads measured in tens of thousands kips, there is little room in the design of high-rise buildings for excessively complex thoughts. Indeed, the better high-rise buildings carry the universal traits of simplicity of thought and clarity of expression.It does not follow that there is no room for grand thoughts. Indeed, it is with such grand thoughts that the new family of high-rise buildings has evolved. Perhaps more important, the new concepts of but a few years ago have become commonplace in today’ s technology.Omitting some concepts that are related strictly to the materials of construction, the most commonly used structural systems used in high-rise buildings can be categorized as follows:1.Moment-resisting frames.2.Braced frames, including eccentrically braced frames.3.Shear walls, including steel plate shear walls.4.Tube-in-tube structures.5.Core-interactive structures.6.Cellular or bundled-tube systems.Particularly with the recent trend toward more complex forms, but in response also to the need for increased stiffness to resist the forces from wind and earthquake, most high-rise buildings have structural systems built up of combinations of frames, braced bents, shear walls, and related systems. Further, for the taller buildings, the majorities are composed of interactive elements in three-dimensional arrays.The method of combining these elements is the very essence of the design process for high-rise buildings. These combinations need evolve in response to environmental, functional, and cost considerations so as to provide efficient structures that provoke the architectural development to new heights. This is not to say that imaginative structural design can create great architecture. To the contrary, many examples of fine architecture have been created with only moderate support from the structural engineer, while only fine structure, not great architecture, can be developed without the genius and the leadership of a talented architect. In any event, the best of both is needed to formulate a truly extraordinary design of a high-rise building.While comprehensive discussions of these seven systems are generally available in the literature, further discussion is warranted here .The essence of the design process is distributed throughout the discussion.Moment-Resisting FramesPerhaps the most commonly used system in low-to medium-rise buildings, the moment-resisting frame, is characterized by linear horizontal and vertical members connected essentially rigidly at their joints. Such frames are used as a stand-alone system or in combination with other systems so as to provide the needed resistance to horizontal loads. In the taller of high-rise buildings, the system is likely to be found inappropriate for a stand-alone system, this because of the difficulty in mobilizing sufficient stiffness under lateral forces.Analysis can be accomplished by STRESS, STRUDL, or a host of other appropriate computer programs; analysis by the so-called portal method of the cantilever method has no place in today’s technology.Because of the intrinsic flexibility of the column/girder intersection, and because preliminary designs should aim to highlight weaknesses of systems, it is not unusual to use center-to-center dimensions for the frame in the preliminary analysis. Of course, in the latter phases of design, a realistic appraisal in-joint deformation is essential.Braced Frame sThe braced frame, intrinsically stiffer than the moment –resisting frame, finds also greater application to higher-rise buildings. The system is characterized by linear horizontal, vertical, and diagonal members, connected simply or rigidly at their joints. It is used commonly inconjunction with other systems for taller buildings and as a stand-alone system in low-to medium-rise buildings.While the use of structural steel in braced frames is common, concrete frames are more likely to be of the larger-scale variety.Of special interest in areas of high seismicity is the use of the eccentric braced frame.Again, analysis can be by STRESS, STRUDL, or any one of a series of two –or three dimensional analysis computer programs. And again, center-to-center dimensions are used commonly in the preliminary analysis. Shear wallsThe shear wall is yet another step forward along a progression of ever-stiffer structural systems. The system is characterized by relatively thin, generally but not always concrete elements that provide both structural strength and separation between building functions.In high-rise buildings, shear wall systems tend to have a relatively high aspect ratio, that is, their height tends to be large compared to their width. Lacking tension in the foundation system, any structural element is limited in its ability to resist overturning moment by the width of the system and by the gravity load supported by the element. Limited to a narrow overturning, One obvious use of the system, which does have the needed width, is in the exterior walls of building, where the requirement for windows is kept small.Structural steel shear walls, generally stiffened against buckling by a concrete overlay, have found application where shear loads are high. The system, intrinsically more economical than steel bracing, is particularly effective in carrying shear loads down through the taller floors in the areas immediately above grade. The system has the further advantage of having high ductility a feature of particular importance in areas of high seismicity.The analysis of shear wall systems is made complex because of the inevitable presence of large openings through these walls. Preliminary analysis can be by truss-analogy, by the finite element method, or by making use of a proprietary computer program designed to consider the interaction, or coupling, of shear walls.Framed or Braced TubesThe concept of the framed or braced or braced tube erupted into the technology with the IBM Building in Pittsburgh, but was followed immediately with the twin 110-story towers of the World Trade Center, New York and a number of other buildings .The system is characterized by three –dimensional frames, braced frames, or shear walls, forming a closed surface more or less cylindrical in nature, but of nearly any plan configuration. Because those columns that resist lateral forces are placed as far as possible from the cancroids of the system, the overall moment of inertia is increased and stiffness is very high.The analysis of tubular structures is done using three-dimensional concepts, or by two- dimensional analogy, where possible, whichever method is used, it must be capable of accounting for the effects of shear lag.The presence of shear lag, detected first in aircraft structures, is a serious limitation in the stiffness of framed tubes. The concept has limited recent applications of framed tubes to the shear of 60 stories. Designers have developed various techniques for reducing the effects of shear lag, most noticeably the use of belt trusses. This system finds application in buildings perhaps 40stories and higher. However, except for possible aesthetic considerations, belt trusses interfere with nearly every building function associated with the outside wall; the trusses are placed often at mechanical floors, mush to the disapproval of the designers of the mechanical systems. Nevertheless, as a cost-effective structural system, the belt truss works well and will likely find continued approval from designers. Numerous studies have sought to optimize the location of these trusses, with the optimum location very dependent on the number of trusses provided. Experience would indicate, however, that the location of these trusses is provided by the optimization of mechanical systems and by aesthetic considerations, as the economics of the structural system is not highly sensitive to belt truss location.Tube-in-Tube StructuresThe tubular framing system mobilizes every column in the exterior wallin resisting over-turning and shearing forces. The term‘tube-in-tube’is largely self-explanatory in that a second ring of columns, the ring surrounding the central service core of the building, is used as an inner framed or braced tube. The purpose of the second tube is to increase resistance to over turning and to increase lateral stiffness. The tubes need not be of the same character; that is, one tube could be framed, while the other could be braced.In considering this system, is important to understand clearly the difference between the shear and the flexural components of deflection, the terms being taken from beam analogy. In a framed tube, the shear component of deflection is associated with the bending deformation of columns and girders , the webs of the framed tube while the flexural component is associated with the axial shortening and lengthening of columns , the flanges of the framed tube. In a braced tube, the shear component of deflection is associated with the axial deformation of diagonals while the flexural component of deflection is associated with the axial shortening and lengthening of columns.Following beam analogy, if plane surfaces remain plane , the floor slabs,then axial stresses in the columns of the outer tube, being farther form the neutral axis, will be substantially larger than the axial stresses in the inner tube. However, in the tube-in-tube design, when optimized, the axial stresses in the inner ring of columns may be as high, or evenhigher, than the axial stresses in the outer ring. This seeming anomaly is associated with differences in the shearing component of stiffness between the two systems. This is easiest to under-stand where the inner tube is conceived as a braced , shear-stiff tube while the outer tube is conceived as a framed , shear-flexible tube.Core Interactive StructuresCore interactive structures are a special case of a tube-in-tube wherein the two tubes are coupled together with some form of three-dimensional space frame. Indeed, the system is used often wherein the shear stiffness of the outer tube is zero. The United States Steel Building, Pittsburgh, illustrates the system very well. Here, the inner tube is a braced frame, the outer tube has no shear stiffness, and the two systems are coupled if they were considered as systems passing in a straight line from the “hat” structure. Note that the exterior columns would be improperly modeled if they were considered as systems passing in a straight line from the “hat” to the foundations; these columns are perhaps 15% stiffer as they follow the elastic curve of the braced core. Note also that the axial forces associated with the lateral forces in the inner columns change from tension to compression over the height of the tube, with the inflection point at about 5/8 of the height of the tube. The outer columns, of course, carry the same axial force under lateral load for the full height of the columns because the columns because the shearstiffness of the system is close to zero.The space structures of outrigger girders or trusses, that connect the inner tube to the outer tube, are located often at several levels in the building. The AT&T headquarters is an example of an astonishing array of interactive elements:1.The structural system is 94 ft wide, 196ft long, and 601ft high.2.Two inner tubes are provided, each 31ft by 40 ft , centered 90 ft apartin the long direction of the building.3.The inner tubes are braced in the short direction, but with zero shearstiffness in the long direction.4.A single outer tube is supplied, which encircles the buildingperimeter.5.The outer tube is a moment-resisting frame, but with zero shearstiffness for the center50ft of each of the long sides.6.A space-truss hat structure is provided at the top of the building.7.A similar space truss is located near the bottom of the building8.The entire assembly is laterally supported at the base on twinsteel-plate tubes, because the shear stiffness of the outer tube goes to zero at the base of the building.Cellular structuresA classic example of a cellular structure is the Sears Tower, Chicago,a bundled tube structure of nine separate tubes. While the Sears Towercontains nine nearly identical tubes, the basic structural system has special application for buildings of irregular shape, as the several tubes need not be similar in plan shape, It is not uncommon that some of the individual tubes one of the strengths and one of the weaknesses of the system.This special weakness of this system, particularly in framed tubes, has to do with the concept of differential column shortening. The shortening of a column under load is given by the expression△=ΣfL/EFor buildings of 12 ft floor-to-floor distances and an average compressive stress of 15 ksi 138MPa, the shortening of a column under load is 15 1212/29,000 or per story. At 50 stories, the column will have shortened to in. 94mm less than its unstressed length. Where one cell of a bundled tube system is, say, 50stories high and an adjacent cell is, say, 100stories high, those columns near the boundary between .the two systems need to have this differential deflection reconciled.Major structural work has been found to be needed at such locations. In at least one building, the Rialto Project, Melbourne, the structural engineer found it necessary to vertically pre-stress the lower height columns so as to reconcile the differential deflections of columns in close proximity with the post-tensioning of the shorter column simulatingthe weight to be added on to adjacent, higher columns.二、原文翻译：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;这种框架用作独立的体系,或者和其他体系结合起来使用,以便提供所需要水平荷载抵抗力;对于较高的高层建筑,可能会发现该本系不宜作为独立体系,这是因为在侧向力的作用下难以调动足够的刚度;我们可以利用STRESS,STRUDL 或者其他大量合适的计算机程序进行结构分析;所谓的门架法分析或悬臂法分析在当今的技术中无一席之地,由于柱梁节点固有柔性,并且由于初步设计应该力求突出体系的弱点,所以在初析中使用框架的中心距尺寸设计是司空惯的;当然,在设计的后期阶段,实际地评价结点的变形很有必要;支撑框架支撑框架实际上刚度比抗弯矩框架强,在高层建筑中也得到更广泛的应用;这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色,它通常与其他体系共同用于较高的建筑,并且作为一种独立的体系用在低、中高度的建筑中;尤其引人关注的是,在强震区使用偏心支撑框架;此外,可以利用STRESS,STRUDL,或一系列二维或三维计算机分析程序中的任何一种进行结构分析;另外,初步分析中常用中心距尺寸;剪力墙剪力墙在加强结构体系刚性的发展过程中又前进了一步;该体系的特点是具有相当薄的,通常是而不总是混凝土的构件,这种构件既可提供结构强度,又可提供建筑物功能上的分隔;在高层建筑中,剪力墙体系趋向于具有相对大的高宽经,即与宽度相比,其高度偏大;由于基础体系缺少应力,任何一种结构构件抗倾覆弯矩的能力都受到体系的宽度和构件承受的重力荷载的限制;由于剪力墙宽度狭狭窄受限,所以需要以某种方式加以扩大,以便提从所需的抗倾覆能力;在窗户需要量小的建筑物外墙中明显地使用了这种确有所需要宽度的体系;钢结构剪力墙通常由混凝土覆盖层来加强以抵抗失稳,这在剪切荷载大的地方已得到应用;这种体系实际上比钢支撑经济,对于使剪切荷载由位于地面正上方区域内比较高的楼层向下移特别有效;这种体系还具有高延性之优点,这种特性在强震区特别重要;由于这些墙内必然出同一些大孔,使得剪力墙体系分析变得错综复杂;可以通过桁架模似法、有限元法,或者通过利用为考虑剪力墙的交互作用或扭转功能设计的专门计处机程序进行初步分析框架或支撑式筒体结构：框架或支撑式筒体最先应用于IBM公司在Pittsburgh的一幢办公楼,随后立即被应用于纽约双子座的110层世界贸易中心摩天大楼和其他的建筑中;这种系统有以下几个显着的特征：三维结构、支撑式结构、或由剪力墙形成的一个性质上差不多是圆柱体的闭合曲面,但又有任意的平面构成;由于这些抵抗侧向荷载的柱子差不多都被设置在整个系统的中心,所以整体的惯性得到提高,刚度也是很大的;在可能的情况下,通过三维概念的应用、二维的类比,我们可以进行筒体结构的分析;不管应用那种方法,都必须考虑剪力滞后的影响;这种最先在航天器结构中研究的剪力滞后出现后,对筒体结构的刚度是一个很大的限制;这种观念已经影响了筒体结构在60层以上建筑中的应用;设计者已经开发出了很多的技术,用以减小剪力滞后的影响,这其中最有名的是桁架的应用;框架或支撑式筒体在40层或稍高的建筑中找到了自己的用武之地;除了一些美观的考虑外,桁架几乎很少涉及与外墙联系的每个建筑功能,而悬索一般设置在机械的地板上,这就令机械体系设计师们很不赞成;但是,作为一个性价比较好的结构体系,桁架能充分发挥它的性能,所以它会得到设计师们持续的支持;由于其最佳位置正取决于所提供的桁架的数量,因此很多研究已经试图完善这些构件的位置;实验表明：由于这种结构体系的经济性并不十分受桁架位置的影响,所以这些桁架的位置主要取决于机械系统的完善,审美的要求,筒中筒结构：筒体结构系统能使外墙中的柱具有灵活性,用以抵抗颠覆和剪切力;“筒中筒”这个名字顾名思义就是在建筑物的核心承重部分又被包围了第二层的一系列柱子,它们被当作是框架和支撑筒来使用;配置第二层柱的目的是增强抗颠覆能力和增大侧移刚度;这些筒体不是同样的功能,也就是说,有些筒体是结构的,而有些筒体是用来支撑的;在考虑这种筒体时,清楚的认识和区别变形的剪切和弯曲分量是很重要的,这源于对梁的对比分析;在结构筒中,剪切构件的偏角和柱、纵梁例如：结构筒中的网等的弯曲有关,同时,弯曲构件的偏角取决于柱子的轴心压缩和延伸例如：结构筒的边缘等;在支撑筒中,剪切构件的偏角和对角线的轴心变形有关,而弯曲构件的偏角则与柱子的轴心压缩和延伸有关;根据梁的对比分析,如果平面保持原形例如：厚楼板,那么外层筒中柱的轴心压力就会与中心筒柱的轴心压力相差甚远,而且稳定的大于中心筒;但是在筒中筒结构的设计中,当发展到极限时,内部轴心压力会很高的,甚至远远大于外部的柱子;这种反常的现象是由于两种体系中的剪切构件的刚度不同;这很容易去理解,内筒可以看成是一个支撑或者说是剪切刚性的筒,而外筒可以看成是一个结构或者说是剪切弹性的筒;核心交互式结构：核心交互式结构属于两个筒与某些形式的三维空间框架相配合的筒中筒特殊情况;事实上,这种体系常用于那种外筒剪切刚度为零的结构;位于Pittsburgh的美国钢铁大楼证实了这种体系是能很好的工作的;在核心交互式结构中,内筒是一个支撑结构,外筒没有任何剪切刚度,而且两种结构体系能通过一个空间结构或“帽”式结构共同起作用;需要指出的是,如果把外部的柱子看成是一种从“帽”到基础的直线体系,这将是不合适的；根据支撑核心的弹性曲线,这些柱子只发挥了刚度的15%;同样需要指出的是,内柱中与侧向力有关的轴向力沿筒高度由拉力变为压力,同时变化点位于筒高度的约5/8处;当然,外柱也传递相同的轴向力,这种轴向力低于作用在整个柱子高度的侧向荷载,因为这个体系的剪切刚度接近于零;把内外筒相连接的空间结构、悬臂梁或桁架经常遵照一些规范来布置;美国电话电报总局就是一个布置交互式构件的生动例子;1、结构体系长米,宽米,高米;2、布置了两个筒,每个筒的尺寸是米×米,在长方向上有米的间隔;3、在短方向上内筒被支撑起来,但是在长方向上没有剪切刚度;4、环绕着建筑物布置了一个外筒;5、外筒是一个瞬时抵抗结构,但是在每个长方向的中心米都没有剪切刚度;6、在建筑的顶部布置了一个空间桁架构成的“帽式”结构;7、在建筑的底部布置了一个相似的空间桁架结构;8、由于外筒的剪切刚度在建筑的底部接近零,整个建筑基本上由两个钢板筒来支持;框格体系或束筒体系结构：位于美国芝加哥的西尔斯大厦是箱式结构的经典之作,它由九个相互独立的筒组成的一个集中筒;由于西尔斯大厦包括九个几乎垂直的筒,而且筒在平面上无须相似,基本的结构体系在不规则形状的建筑中得到特别的应用;一些单个的筒高于建筑一点或很多是很常见的;事实上,这种体系的重要特征就在于它既有坚固的一面,也有脆弱的一面;这种体系的脆弱,特别是在结构筒中,与柱子的压缩变形有很大的关系,柱子的压缩变形有下式计算：△=ΣfL/E对于那些层高为米左右和平均压力为138MPa的建筑,在荷载作用下每层柱子的压缩变形为1512/29000或毫米;在第50层柱子会压缩94毫米,小于它未受压的长度;这些柱子在50层的时候和100层的时候的变形是不一样的,位于这两种体系之间接近于边缘的那些柱需要使这种不均匀的变形得以调解;主要的结构工作都集中在布置中;在Melbourne的Rialto项目中,结构工程师发现至少有一幢建筑,很有必要垂直预压低高度的柱子,以便使柱不均匀的变形差得以调解,调解的方法近似于后拉伸法,即较短的柱转移重量到较高的邻柱上;。

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