岩土工程 英语论文
关于土木工程英语作文
关于土木工程英语作文英文回答：Civil engineering is a broad and challenging field that encompasses the design, construction, and maintenance of the built environment. As a civil engineer, I have the privilege of working on a wide range of projects, from bridges and roads to buildings and water treatment plants.One of the most rewarding aspects of civil engineering is the opportunity to make a tangible difference in the world. The structures that we design and build have adirect impact on the lives of people and communities. For example, a new bridge can connect isolated areas, a new road can improve access to essential services, and a new building can provide shelter and comfort for those who need it.Another aspect of civil engineering that I find particularly interesting is the challenge of constantlyinnovating. The field is constantly evolving, and new technologies and materials are emerging all the time. This means that civil engineers must be adaptable and willing to learn new things.Of course, civil engineering is not without its challenges. One of the biggest challenges is the need to balance the competing demands of safety, cost, and sustainability. Civil engineers must be able to design structures that are safe and reliable, but they must also be mindful of the cost of construction and the environmental impact of the materials used.Another challenge is the need to work with a variety of stakeholders, including clients, architects, contractors, and government agencies. Civil engineers must be able to communicate effectively with all of these stakeholders to ensure that the project is completed successfully.Despite the challenges, civil engineering is a rewarding and fulfilling career. I am proud to be a part of a profession that makes a real difference in the world.中文回答：土木工程是一个既广泛又富有挑战性的领域，涵盖了建造环境的设计、建造和维护。
岩土工程专业翻译英文原文和译文
According to the yield design (or limit analysis) reasoning, the above structure will remain safe under a given vertical load Q(force per unit length along the Oz axis), if one can exhibit throughout the rock mass a stress distribution which satisfies the equilibrium equations along with the stress boundary conditions,while complying with the strength requirement expressed at any point of the structure. This problem amounts to evaluating the ultimate load Q﹢ beyond which failure will occur, or equivalently within which its stability is ensured. Due to the strong heterogeneity of the jointed rock mass, insurmountable difficulties are likely to arise when trying to implement the above reasoning directly. As regards, for instance, the case where the strength properties of the joints are considerably lower than those of the rock matrix, the implementation of a kinematic approach would require the use of failure mechanisms involving velocity jumps
岩土工程中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)原文:Safety Assurance for Challenging Geotechnical Civil Engineering Constructions in Urban AreasAbstractSafety is the most important aspect during design, construction and service time of any structure, especially for challenging projects like high-rise buildings and tunnels in urban areas. A high level design considering the soil-structure interaction, based on a qualified soil investigation is required for a safe and optimised design. Dueto the complexity of geotechnical constructions the safety assurance guaranteed by the 4-eye-principle is essential. The 4-eye-principle consists of an independent peer review by publicly certified experts combined with the observational method. The paper presents the fundamental aspects of safety assurance by the 4-eye-principle. The application is explained on several examples, as deep excavations, complex foundation systems for high-rise buildings and tunnel constructions in urban areas. The experiences made in the planning, design and construction phases are explained and for new inner urban projects recommendations are given.Key words: Natural Asset; Financial Value; Neural Network1.IntroductionA safety design and construction of challenging projects in urban areas is based on the following main aspects:Qualified experts for planning, design and construction;Interaction between architects, structural engineers and geotechnical engineers;Adequate soil investigation;Design of deep foundation systems using the FiniteElement-Method (FEM) in combination with enhanced in-situ load tests for calibrating the soil parameters used in the numerical simulations;Quality assurance by an independent peer review process and the observational method (4-eye-principle).These facts will be explained by large construction projects which are located in difficult soil and groundwater conditions.2.The 4-Eye-PrincipleThe basis for safety assurance is the 4-eye-principle. This 4-eye-principle is a process of an independent peer review as shown in Figure 1. It consists of 3 parts. The investor, the experts for planning and design and the construction company belong to the first division. Planning and design are done accordingto the requirements of the investor and all relevant documents to obtain the building permission are prepared. The building authorities are the second part and are responsible for the buildingpermission which is given to the investor. The thirddivision consists of the publicly certified experts.They are appointed by the building authorities but work as independent experts. They are responsible for the technical supervision of the planning, design and the construction.In order to achieve the license as a publicly certified expert for geotechnical engineering by the building authorities intensive studies of geotechnical engineering in university and large experiences in geotechnical engineering with special knowledge about the soil-structure interaction have to be proven.The independent peer review by publicly certified experts for geotechnical engineering makes sure that all information including the results of the soil investigation consisting of labor field tests and the boundary conditions defined for the geotechnical design are complete and correct.In the case of a defect or collapse the publicly certified expert for geotechnical engineering can be involved as an independent expert to find out the reasons for the defect or damage and to develop a concept for stabilization and reconstruction [1].For all difficult projects an independent peer review is essential for the successful realization of the project.3.Observational MethodThe observational method is practical to projects with difficult boundary conditions for verification of the design during the construction time and, if necessary, during service time. For example in the European Standard Eurocode 7 (EC 7) the effect and the boundary conditions of the observational method are defined.The application of the observational method is recommended for the following types of construction projects [2]:very complicated/complex projects;projects with a distinctive soil-structure-interaction,e.g. mixed shallow and deep foundations, retaining walls for deep excavations, Combined Pile-Raft Foundations (CPRFs);projects with a high and variable water pressure;complex interaction situations consisting of ground,excavation and neighbouring buildings and structures;projects with pore-water pressures reducing the stability;projects on slopes.The observational method is always a combination of the common geotechnical investigations before and during the construction phase together with the theoretical modeling and a plan of contingency actions(Figure 2). Only monitoring to ensure the stability and the service ability of the structure is not sufficient and,according to the standardization, not permitted for this purpose. Overall the observational method is an institutionalized controlling instrument to verify the soil and rock mechanical modeling [3,4].The identification of all potential failure mechanismsis essential for defining the measure concept. The concept has to be designed in that way that all these mechanisms can be observed. The measurements need to beof an adequate accuracy to allow the identification ocritical tendencies. The required accuracy as well as the boundary values need to be identified within the design phase of the observational method . Contingency actions needs to be planned in the design phase of the observational method and depend on the ductility of the systems.The observational method must not be seen as a potential alternative for a comprehensive soil investigation campaign. A comprehensive soil investigation campaignis in any way of essential importance. Additionally the observational method is a tool of quality assurance and allows the verification of the parameters and calculations applied in the design phase. The observational method helps to achieve an economic and save construction [5].4.In-Situ Load TestOn project and site related soil investigations with coredrillings and laboratory tests the soil parameters are determined. Laboratory tests are important and essential for the initial definition of soil mechanical properties of the soil layer, but usually not sufficient for an entire and realistic capture of the complex conditions, caused by theinteraction of subsoil and construction [6].In order to reliably determine the ultimate bearing capacity of piles, load tests need to be carried out [7]. Forpile load tests often very high counter weights or strong anchor systems are necessary. By using the Osterberg method high loads can be reached without install inganchors or counter weights. Hydraulic jacks induce the load in the pile using the pile itself partly as abutment.The results of the field tests allow a calibration of the numerical simulations.The principle scheme of pile load tests is shown in Figure 3.5.Examples for Engineering Practice5.1. Classic Pile Foundation for a High-Rise Building in Frankfurt Clay and LimestoneIn the downtown of Frankfurt am Main, Germany, on aconstruction site of 17,400 m2 the high-rise buildingproject “PalaisQuartier” has been realized (Figure 4). The construction was finished in 2010.The complex consists of several structures with a total of 180,000 m2 floor space, there of 60,000 m2 underground (Figure 5). The project includes the historic building “Thurn-und Taxis-Palais” whose facade has been preserved (Unit A). The office building (Unit B),which is the highest building of the project with a height of 136 m has 34 floors each with a floor space of 1340 m2. The hotel building (Unit C) has a height of 99 m with 24 upper floors. The retail area (Unit D)runs along the total length of the eastern part of the site and consists of eight upper floors with a total height of 43 m.The underground parking garage with five floors spans across the complete project area. With an 8 m high first sublevel, partially with mezzanine floor, and four more sub-levels the foundation depth results to 22 m below ground level. There by excavation bottom is at 80m above sea level (msl). A total of 302 foundation piles(diameter up to 1.86 m, length up to 27 m) reach down to depths of 53.2 m to 70.1 m. above sea level depending on the structural requirements.The pile head of the 543 retaining wall piles (diameter1.5 m, length up to 38 m)were located between 94.1 m and 99.6 m above sea level, the pile base was between 59.8 m and 73.4 m above sea level depending on the structural requirements. As shown in the sectional view(Figure 6), the upper part of the piles is in the Frankfurt Clay and the base of the piles is set in the rocky Frankfurt Limestone.Regarding the large number of piles and the high pile loads a pile load test has been carried out for optimization of the classic pile foundation. Osterberg-Cells(O-Cells) have been installed in two levels in order to assess the influence of pile shaft grouting on the limit skin friction of the piles in the Frankfurt Limestone(Figure 6). The test pile with a total length of 12.9 m and a diameter of 1.68 m consist of three segments and has been installed in the Frankfurt Limestone layer 31.7 m below ground level. The upper pile segment above the upper cell level and the middle pile segment between the two cell levels can be tested independently. In the first phase of the test the upper part was loaded by using the middle and the lower part as abutment. A limit of 24 MN could be reached (Figure 7). The upper segment was lifted about 1.5 cm, the settlement of the middle and lower part was 1.0 cm. The mobilized shaft friction was about 830 kN/m2.Subsequently the upper pile segment was uncoupled by discharging the upper cell level. In the second test phase the middle pile segment was loaded by using the lower segment as abutment. The limit load of the middle segment with shaft grouting was 27.5 MN (Figure 7).The skin friction was 1040 kN/m2, this means 24% higher than without shaft grouting. Based on the results of the pile load test using O-Cells the majority of the 290 foundation piles were made by applying shaft grouting. Due to pile load test the total length of was reduced significantly.5.2. CPRF for a High-Rise Building in Clay MarlIn the scope of the project Mirax Plaza in Kiev, Ukraine,2 high-rise buildings, each of them 192 m (46 storeys)high, a shopping and entertainment mall and an underground parking are under construction (Figure 8). The area of the project is about 294,000 m2 and cuts a 30 m high natural slope.The geotechnical investigations have been executed 70m deep. The soil conditions at the construction site are as follows: fill to a depth of 2 m to 3mquaternary silty sand and sandy silt with a thickness of 5 m to 10 m tertiary silt and sand (Charkow and Poltaw formation) with a thickness of 0 m to 24 m tertiary clayey silt and clay marl of the Kiev and But schak formation with a thickness of about 20 m tertiary fine sand of the But schak formation up to the investigation depthThe ground water level is in a depth of about 2 m below the ground surface. The soil conditions and a cross section of the project are shown in Figure 9.For verification of the shaft and base resistance of the deep foundation elements and for calibration of the numerical simulations pile load tests have been carried out on the construction yard. The piles had a diameter of 0.82 m and a length of about 10 m to 44 m. Using the results of the load tests the back analysis for verification of the FEM simulations was done. The soil properties in accordance with the results of the back analysis were partly 3 times higher than indicated in the geotechnical report. Figure 10 shows the results of the load test No. 2 and the numerical back analysis. Measurement and calculation show a good accordance.The obtained results of the pile load tests and of the executed back analysis were applied in 3-dimensionalFEM-simulations of the foundation for Tower A, taking advantage of the symmetry of the footprint of the building. The overall load of the Tower A is about 2200 MN and the area of the foundation about 2000 m2 (Figure11).The foundation design considers a CPRF with 64 barrettes with 33 m length and a cross section of 2.8 m × 0.8m. The raft of 3 m thickness is located in Kiev Clay Marl at about 10 m depth below the ground surface. The barrettes are penetrating the layer of Kiev Clay Marl reaching the Butschak Sands.The calculated loads on the barrettes were in the range of 22.1 MN to 44.5 MN. The load on the outer barrettes was about 41.2 MN to 44.5 MN which significantly exceeds the loads on the inner barrettes with the maximum value of 30.7 MN. This behavior is typical for a CPRF.The outer deep foundation elements take more loads because of their higher stiffness due to the higher volume of the activated soil. The CPRF coefficient is 0.88 =CPRF . Maximum settlements of about 12 cm werecalculated due to the settlement-relevant load of 85% of the total design load. The pressure under the foundation raft is calculated in the most areas not exceeding 200 kN/m2, at the raft edge the pressure reaches 400 kN/m2.The calculated base pressure of the outer barrettes has anaverage of 5100 kN/m2 and for inner barrettes an average of 4130 kN/m2. The mobilized shaft resistance increases with the depth reaching 180 kN/m2 for outer barrettes and 150 kN/m2 for inner barrettes.During the construction of Mirax Plaza the observational method according to EC 7 is applied. Especially the distribution of the loads between the barrettes and the raft is monitored. For this reason 3 earth pressure devices were installed under the raft and 2 barrettes (most loaded outer barrette and average loaded inner barrette) were instrumented over the length.In the scope of the project Mirax Plaza the new allowable shaft resistance and base resistance were defined for typical soil layers in Kiev. This unique experience will be used for the skyscrapers of new generation in Ukraine.The CPRF of the high-rise building project MiraxPlaza represents the first authorized CPRF in the Ukraine. Using the advanced optimization approaches and taking advantage of the positive effect of CPRF the number of barrettes could be reduced from 120 barrettes with 40 mlength to 64 barrettes with 33 m length. The foundation optimization leads to considerable decrease of the utilized resources (cement, aggregates, water, energy etc.)and cost savings of about 3.3 Million US$.译文:安全保证岩土公民发起挑战工程建设在城市地区摘要安全是最重要的方面在设计、施工和服务时间的任何结构,特别是对具有挑战性的项目,如高层建筑和隧道在城市地区。
地质与岩土工程专业英语论文tb
岩土工程英语作业姓名：汤彪学号：013621814102班级：0133018141SHORT COMMUNICATIONS ANALYTICAL METHOD FOR ANALYSIS OFSLOPE STABILITYJINGGANG CAOs AND MUSHARRAF M. ZAMAN*tSchool of Civil Engineering and Environmental Science,University of Oklahoma, Norman, OK 73019, U.S.A.SUMMARYAn analytical method is presented for analysis of slopestability involving cohesive and non-cohesive soils.Earthquakeeffects are considered in an approximate manner in terms ofseismic coe$cient-dependent forces. Two kinds of failure surfaces areconsidered in this study: a planar failure surface, and acircular failure surface. The proposed method can be viewed asan extension of the method of slices, but it provides a moreaccurate etreatment of the forces because they are representedin an integral form. The factor of safety is obtained by usingthe minimization technique rather than by a trial and errorapproach used commonly.The factors of safety obtained by the analytical method arefound to be in good agreement with those determined by the localminimum factor-of-safety, Bishop's, and the method of slices. Theproposed method is straightforward, easy to use, and lesstime-consuming in locating the most critical slip surface andcalculating the minimum factor of safety for a given slope.Copyright ( 1999) John Wiley & Sons, Ltd.Key words: analytical method; slope stability; cohesive andnon-cohesive soils; dynamic effect; planar failure surface;circular failure surface; minimization technique;factor-of-safety.INTRODUCTIONOne of the earliest analyses which is still used in manyapplications involving earth pressure was proposed by Coulomb in1773. His solution approach for earth pressures against retainingwalls used plane sliding surfaces, which was extended to analysis of slopes in 1820 by Francais. By about 1840, experience with cuttings and embankments for railways and canals in England and France began to show that many failure surfaces in clay were not plane, but signi"cantly curved. In 1916, curved failure surfaces were again reported from the failure of quay structures in Sweden. In analyzing these failures, cylindrical surfaces were used and the sliding soil mass was divided into a number of vertical slices. The procedure is still sometimes referred to as the Swedish method of slices. By mid-1950s further attention was given to the methods of analysis usingcircular and non-circular sliding surfaces . In recent years, numerical methods have also been used in the slope stability analysis with the unprecedented development of computer hardware and software. Optimization techniques were used by Nguyen,10 and Chen and Shao. While finite element analyses have great potential for modelling field conditions realistically, they usually require signi"cant e!ort and cost that may not be justi"ed in some cases.The practice of dividing a sliding mass into a number of slices is still in use, and it forms the basis of many modern analyses.1,9 However, most of these methods use the sums of the terms for all slices which make the calculations involved in slope stability analysis a repetitive and laborious process.Locating the slip surface having the lowest factor of safety is an important part of analyzing a slope stability problem. A number of computer techniques have been developed to automate as much of this process as possible. Most computer programs use systematic changes in the position of the center of the circle and the length of the radius to find the critical circle.Unless there are geological controls that constrain the slip surface to a noncircular shape, it can be assumed with a reasonablecertainty that the slip surface is circular.9 Spencer (1969) found that consideration of circular slip surfaces was as critical as logarithmic spiral slip surfaces for all practical purposes. Celestino and Duncan (1981), and Spencer (1981) found that, in analyses where the slip surface was allowed to take any shape, the critical slip surface found by the search was essentially circular. Chen (1970), Baker and Garber (1977), and Chen and Liu maintained that the critical slip surface is actually a log spiral. Chen and Liu12 developed semi-analytical solutions using variational calculus, for slope stability analysis with a logspiral failure surface in the coordinate system. Earthquake e!ects were approximated in terms of inertiaforces (vertical and horizontal) defined by the corresponding seismic coe$cients. Although this is one of the comprehensive and useful methods, use of /-coordinate system makes the solution procedure attainable but very complicated. Also, the solutions are obtained via numerical means at the end. Chen and Liu12 have listed many constraints, stemming from physical considerations that need to be taken into account when using their approach in analyzing a slope stability problem.The circular slip surfaces are employed for analysis of clayey slopes, within the framework of an analytical approach, in this study. The proposed method is more straightforward and simpler than that developed by Chen and Liu. Earthquake effects are included in the analysis in an approximate manner within the general framework of static loading. It is acknowledged that earthquake effects might be better modeled by including accumulated displacements in the analysis. The planar slip surfaces are employed for analysis of sandy slopes. A closed-form expression for the factor of safety is developed, which is diferent from that developed by Das.STABILITY ANALYSIS CONDITIONS AND SOIL STRENGTHThere are two broad classes of soils. In coarse-grained cohesionless sands and gravels, the shear strength is directly proportional to the stress level:''tan f τσθ= （1）where fτ is the shear stress at failure, /σ the effectivenormal stress at failure, and /θ the effective angle of shearing resistance of soil.In fine-grained clays and silty clays, the strength depends on changes in pore water pressures or pore water volumes which take place during shearing. Under undrained conditions, the shear strength cu is largely independent of pressure, that is u θ=0. When drainage is permitted, however, both &cohesive' and &frictional' components ''(,)c θ are observed. In this case the shear strength is given by(2)Consideration of the shear strengths of soils under drained and undrained conditions, and of the conditions that will control drainage in the field are important to include in analysis of slopes. Drained conditions are analyzed in terms of effective stresses, using values of ''(,)c θ determined from drained tests, or from undrained tests with pore pressure measurement. Performing drained triaxial tests on clays is frequently impractical because the required testing time can be too long. Direct shear tests or CU tests with pore pressure measurement are often used because the testing time is relatively shorter.Stability analysis involves solution of a problem involving force and/or moment equilibrium.The equilibrium problem can be formulated in terms of (1) total unit weights and boundary water pressure; or (2) buoyant unit weights and seepage forces. The first alternative is a better choice, because it is morestraightforward. Although it is possible, in principle, to usebuoyant unit weights and seepage forces, that procedure is fraught with conceptual diffculties.PLANAR FAILURE SURFACEFailure surfaces in homogeneous or layered non-homogeneous sandy slopes are essentially planar. In some important applications, planar slides may develop. This may happen in slope, where permeable soils such as sandy soil and gravel or some permeable soils with some cohesion yet whose shear strength is principally provided by friction exist. For cohesionless sandy soils, the planar failure surface may happen in slopes where strong planar discontinuities develop, for example in the soil beneath the ground surface in natural hillsides or in man-made cuttings.ααβ图平面破坏Figure 1 shows a typical planar failure slope. From an equilibrium consideration of the slide body ABC by a vertical resolution of forces, the vertical forces across the base of the slide body must equal to weight w. Earthquake effects may be approximated by including a horizontal acceleration kg which produces a horizontal force k= acting through the centroid of the body and neglecting vertical inertia.1 For a slice of unit thickness in the strike direction, the resolved forces of normaland tangential components N and ¹ can be written as(cos sin )N W k αα=-（3）(sin cos )T W k αα=+（4） where is the inclination of the failure surface and w is given by02(tan tan )(tan )(cot cot )2LW x x dx H x dx H γβαγαγαβ=-+-=-⎰⎰ （5） where γ is the unit weight of soil, H the height of slope, cot ,cot ,L H l H βαβ== is the inclination of the slope. Since the length of the slide surface AB is /sin cH α, the resisting force produced by cohesion is cH /sin a. The friction force produced by N is (cos sin )tan W k ααφ-. The total resisting or anti-sliding force is thus given by(cos sin )tan /sin R W k cH ααφα=-+（6）For stability, the downslope slide force ¹ must not exceed the resisting force R of the body. The factor of safety, F s , in the slope can be defined in terms of effective force by ratio R /T, that is1tan 2tan tan (sin cos )sin()s k c F k H k αφαγααβα-=+++- （7） It can be observed from equation (7) that F s is a function of a. Thus the minimum value of F s can be found using Powell's minimization technique18 from equation (7). Das reported a similar expression for F s with k =0, developed directly from equation (2) by assuming that /s f d F ττ=, where f τ is the averageshear strength of the soil, and d τ the average shear stressdeveloped along the potential failure surface.For cohesionless soils where c =0, the safety factor can bereadily written from equation (7) as 1tan tan tan s k F k αφα-=+ （8） It is obvious that the minimum value of F s occurs when a=b, and the failure becomes independent of slope height. For such cases (c=0 and k=0), the factors of safety obtainedfrom the proposed method and from Das are identical.CIRCULAR FAILURE SURFACESlides in medium-stif clays are often deep-seated, and failure takes place along curved surfaces which can be closely approximated in two dimensions by circular surfaces. Figure 2 shows a potential circular sliding surface AB in two dimensions with centre O and radius r . The first step in the analysis is to evaluate the sliding' or disturbing moment M s about the centre of thecircle O . This should include the self-weight w of the sliding mass, and other terms such as crest loadings from stockpiles or railways, and water pressures acting externally to the slope.Earthquake effects is approximated by including a horizontal acceleration kg which produces a horiazontal force k d=acting through the centroid of each slice and neglecting vertical inertia. When the soil above AB is just on the point of sliding, the average shearing resistance which is required along AB for limiting equilibrium is given by equation (2). The slide mass is divided into vertical slices, and a typical slice DEFG is shown. The self-weight of the slice is dW hdx γ=. The method assumes that the resultant forces Xl and Xr on DE and FG , respectively, are equal and opposite, and parallel to the base of the slice EF . It is realized that these assumptions are necessary to keep theanalytical solution of the slope stability problem addressed in this paper achievable and some of these assumptions would lead to restrictions in terms of applications (e.g.earth pressure on retaining walls). However, analytical solutions have a special usefulness in engineering practice, particularly in terms of obtaining approximate solutions. More rigorous methods, e.g. finite element technique, can then be used to pursue a detail solution. Bishop's rigorous method5 introduces a furthernumerical procedure to permit specialcation of interslice shear forces Xl and Xr . Since Xl and Xr are internal forces, ()l r X X -∑ must be zero for the whole section. Resolving prerpendicularly and parallel to EF , one getssin cos T hdx k hdx γαγα=+（9）cos csin N hdx k hdx γαγα=-（10）22arcsin ,x a r a b rα-==+ （11）The force N can produce a maximum shearing resistance when failure occurs:sec (cos sin )tan R cdx hdx k αγααφ=+-（12）The equations of lines AC , CB , and AB Y are given by y22123tan ,,()y x y h y b r x a β===---（13）The sums of the disturbing and resisting moments for all slices can be written as013230(sin cos )()(sin cos )()(sin cos )()ls l lL s c M r h k dx r y y k dx r y y k dx r I kI γααγααγααγ=+=-++-+=+⎰⎰⎰ (14) []02300232sec (cos sin )tan sec ()(cos sin )tan ()(cos sin )tan tan ()lr l l lL c s M r c h k dx r c dx r y y k dx r y y k dx r c r I kI αγααφαγααφγααφϕγφ=+-=+--+--=+-⎰⎰⎰⎰ (15)22cot ,()L H l a r b H β==+-- （16）arcsinarcsin l a a r r ϕ-=+ （17） 1323022()sin ()sin 1(cot )sec 23Ll s L I y y dx y y dxH a b H rααββ=-+-⎡⎤=+-⎢⎥⎣⎦⎰⎰ （18） 13230222222222()cos ()cos tan tan 2()()()623(tan )arcsin (tan )arcsin 221()arcsin()4()()26L l s L I y y dx y y dxb r b r L a r L a r r r L a r a a H a b r r r l a b H r l ab l a H a r r ααββββ=-+-⎡⎤=-+---++⎣⎦-⎛⎫⎛⎫+-+- ⎪ ⎪⎝⎭⎝⎭-⎡⎤--+-+--⎣⎦⎰⎰ （19） The safety factor for this case is usually expressed as the ratio of the maximum available resisting moment to the disturbing moment, that istan ()()c s r s s s c c r I kI M F M I kI ϕγφγ+-==+ (20) When the slope inclination exceeds 543, all failures emerge at the toe of the slope, which is called t oe failure , as shown in Figure 2. However, when the slope height H is relatively large compared with the undrained shear strength or when a hard stratum is under the top of the slope of clayey soil with 03φ<, the slide emerges from the face of the slope, which is called Face failure , as shown in Figure 3. For Face failure , the safety factor F s is the same as ¹oe failure 1s using 0()Hh - instead of H .For flatter slopes, failure is deep-seated and extends to the hard stratum forming the base of the clay layer, which is called Base failure , as shown in Figure 4.1,3 Following the sameprocedure as that for ¹oe failure , one can get the safety factor for Base failure :()''''tan ()c s s s c c r I kI F I kI ϕγφγ+-=+ （21） where t is given by equation (17), and 's I and 'c I are given by()()()0100'0313230322201sin sin sin cot ()()(2)(33)12223l l l s l l I y y xdx y y xdx y y xdx H H bl H l l l l l a b bH H r r r β=-+-+-=+----+-+⎰⎰⎰ (22)()()()()()()[]22222203231030c 4612cot arcsin 2tan arcsin 21arcsin 2cot 412cos cos cos 1100a H a l ab l r r r H H a r r a rb r a H b r H r r Hl d y y d y y d y y I x l l x l l x l --+-+⎪⎭⎫ ⎝⎛⎪⎭⎫ ⎝⎛-+⎪⎭⎫ ⎝⎛-⎪⎭⎫ ⎝⎛----=⎰-+⎰-+⎰-='βββααα（23）其中，()221230,tan ,,y y x y H y b r x a β====---（24） ()220111cot ,cot ,22l a H l a H l a r b H ββ=-=+=+--(25)It can be observed from equations (21)~(25) that the factor of safety F s for a given slope is a function of the parameters a and b. Thus, the minimum value of F s can be found using the Powell's minimization technique.For a given single function f which depends on two independent variables, such as the problem under consideration here, minimization techniques are needed to find the value of these variables where f takes on a minimum value, and then to calculate the corresponding value of f. If one starts at a point P in an N-dimensional space, and proceed from there in some vector direction n, then any function of N variables f (P) can be minimized along the line n by one-dimensional methods. Different methods will difer only by how, at each stage, they choose the next direction n. Powell "rst discovered a direction set method which produces N mutually conjugate directions.Unfortunately, a problem of linear dependence was observed in Powell's algorithm. The modiffed Powell's method avoids a buildup of linear dependence.The closed-form slope stability equation (21) allows the application of an optimization technique to locate the center of the sliding circle (a, b). The minimum factor of safety Fs min then obtained by substituting the values of these parameters into equations (22)~(25) and the results into equation (21), for a base failure problem (Figure 4). While using the Powell's method, the key is to specify some initial values of a and b. Well-assumed initial values of a and b can result in a quick convergence. If the values of a and b are given inappropriately, it may result in a delayed convergence and certain values would not produce a convergent solution. Generally, a should be assumed within$¸, while b should be equal to or greater than H (Figure 4). Similarly, equations(16)~(20) could be used to compute the F s .min for toe failure (Figure 2) and face failure (Figure 3),except ()0H h - is usedinstead of H in the case of face failure .Besides the Powell method, other available minimization methods were also tried in this study such as downhill simplex method, conjugate gradient methods, and variable metric methods. These methods need more rigorous or closer initial values of a and b to the target values than the Powell method. A short computer program was developed using the Powell method to locate the center of the sliding circle (a , b ) and to find the minimum value of F s . This approach of slope stability analysis is straightforward and simple.RESULTS AND COMMENTSThe validity of the analytical method presented in the preceding sections was evaluated using two well-established methods of slope stability analysis. The local minimumfactor-of-safety (1993) method, with the state of the effective stresses in a slope determined by the finite element method with the Drucker-Prager non-linear stress-strain relationship, and Bishop's (1952) method were used to compare the overall factors of safety with respect to the slip surface determined by the proposed analytical method. Assuming k =0 for comparison with the results obtained from the local minimum factor-of-safety and Bishop's method, the results obtained from each of those three methods are listed in Table I.The cases are chosen from the toe failure in a hypothetical homogeneous dry soil slope having a unit weight of 18.5 kN/m3. Two slope configurations were analysed, one 1 : 1 slope and one 2 : 1 slope. Each slope height H was arbitrarily chosen as 8 m. To evaluate the sensitivity of strength parameters on slope stability, cohesion ranging from 5 to 30 kPa and friction angles ranging from 103 to 203 were used in the analyses (Table I). Anumber of critical combinations of c and were found to be unstable for the model slopes studied. The factors of safety obtained by the proposed method are in good agreement with those determined by the local minimum factor-of-safety and Bishop's methods, as shown in Table I.To examine the e!ect of dynamic forces, the analytical method is chosen to analyse a toe failure in a homogeneous clayey slope (Figure 2). The height of the slope H is 13.5 m; the slope inclination b is arctan 1/2; the unit weight of the soil c is 17.3 kN/m3; the friction angle is 17.3KN/m; and the cohesion c is 57.5 kPa. Using the conventional method of slices, Liu obtained theminimum safety factormin 2.09sF= Using the proposed method, one can get the minimum value of safety factor from equation (20) asmin 2.08sF= for k=0, which is very close to the value obtained from the slice method. When k"0)1, 0)15, or 0)2, one cangetmin 1.55,1.37sF=, and 1)23, respectively,which shows the dynamic e!ect on the slope stability to be significant.CONCLUDING REMARKSAn analytical method is presented for analysis of slope stability involving cohesive and noncohesive soils. Earthquake e!ects are considered in an approximate manner in terms of seismic coe$cient-dependent forces. Two kinds of failure surfaces are considered in this study: a planar failure surface, and a circular failure surface. Three failure conditions for circular failure surfacesnamely toe failure, face failure, and base failure are considered for clayey slopes resting on a hard stratum.The proposed method can be viewed as an extension of the method of slices, but it provides a more accurate treatment of the forces because they are represented in an integral form. The factor of safety is obtained by using theminimization technique rather than by a trial and error approach used commonly.The factors of safety obtained from the proposed method are in good agreement with those determined by the local minimum factor-of-safety method (finite element method-based approach), the Bishop method, and the method of slices. A comparison of these methods shows that the proposed analytical approach is more straightforward, less time-consuming, and simple to use. The analytical solutions presented here may be found useful for (a)validating results obtained from other approaches, (b) providinginitial estimates for slope stability, and (c) conducting parametric sensitivity analyses for various geometric and soil conditions.REFERENCES1. D. Brunsden and D. B. Prior. Slope Instability, Wiley, New York, 1984.2. B. F. Walker and R. Fell. Soil Slope Instability and Stabilization, Rotterdam, Sydney, 1987.3. C. Y. Liu. Soil Mechanics, China Railway Press, Beijing, P. R. China, 1990.448 SHORT COMMUNICATIONSCopyright ( 1999 John Wiley & Sons, Ltd. Int. J. Numer. Anal. Meth. Geomech., 23, 439}449 (1999)4. L. W. Abramson. Slope Stability and Stabilization Methods, Wiley, New York, 1996.5. A. W. Bishop. &The use of the slip circle in the stability analysis of slopes', Geotechnique, 5, 7}17 (1955).6. K. E. Petterson. &The early history of circular sliding surfaces', Geotechnique, 5, 275}296 (1956).7. G. Lefebvre, J. M. Duncan and E. L. Wilson.&Three-dimensional "nite element analysis of dams,' J. Soil Mech. Found,ASCE, 99(7), 495}507 (1973).8. Y. Kohgo and T. Yamashita, &Finite element analysis of "ll type dams*stability during construction by using the e!ective stress concept', Proc. Conf. Numer. Meth. in Geomech., ASCE, Vol. 98(7), 1998, pp. 653}665.9. J. M. Duncan. &State of the art: limit equilibrium and "nite-element analysis of slopes', J. Geotech. Engng. ASCE, 122(7), 577}596 (1996).10. V. U. Nguyen. &Determination of critical slope failuresurface', J. Geotech. Engng. ASCE, 111(2), 238}250 (1985).11. Z. Chen and C. Shao. &Evaluation of minimum factor of safety in slope stability analysis,' Can. Geotech. J., 20(1), 104}119 (1988).12. W. F. Chen and X. L. Liu. ¸imit Analysis in Soil Mechanics, Elsevier, New York, 1990.简要的分析斜坡稳定性的方法JINGGANG CAOs 和 MUSHARRAF M. ZAMAN诺曼底的俄克拉荷马大学土木环境工程学院摘要本文给出了解析法对边坡的稳定性分析,包括粘性和混凝土支撑。
土木工程专业英语论文
Building construction concrete crack ofprevention and processingAbstractThe crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure.Keyword: Concrete crack prevention processingForewordConcrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro viewthe crack be also the crack that the concrete often say in the engineering. Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and anti- Shen ability, influence building of external appearance, service life, severity will threat arrive people's life and property safety.A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that.Modern age science research with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside.The reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of width.But at under construction should as far as possible adopt a valid measure control crack creation, make the structure don't appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus.Concrete crack creation of the reason be a lot of and have already transformed to cause of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reasoncause of crack;Have outside carry the crack that the function cause;Protected environment not appropriate the crack etc. caused with chemical effect.Want differentiation to treat in the actual engineering, work°out a problem acco rding to the actual circumstance.In the concrete engineering the familiar crack and the prevention 1.Stem Suo crack and preventionStem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week.In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't negative.Stem Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result:The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pull should dint but creation crack.The relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy creation.Stem the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0.2 mm, the flat surface part much see in the big physical volume concrete andfollow it more in thinner beam plank short todistribute.Stem Suo crack usually the anti- Shen of influence concrete, cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant.Main prevention measure:While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement.Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water.Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can't big in match ratio design give settle of use water quantity.Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time.Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect.Five is a constitution theaccommodation is in the concrete structure of the constringency sew.2.The Su constringency crack and preventionSu constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent appearance.Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 mm.It creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning very small, perhaps concrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again can't resist its constringency, therefore creation cracked.The influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature, wind velocity, relative humidity...etc..Main prevention measure:One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire.Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapseof concrete fall a degree and with easy, decrease cement and water of dosage.Three is to sprinkle before building concrete, water basic level and template even to soak through.Four is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface.Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time.3.Crack and prevention that the chemical reaction causeAlkali bone's anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the reinforced concrete structure of because of chemical reaction but cause of crack.The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open crack.In this kind of crack general emergence concrete structure usage period, once appear very difficult remediable, so should at under construction adopt valid the measure carry on prevention.Main of prevention measure:While being to choose to anticipate with the alkali activity small freestone bone.Two is the in addition which choose to use low lye mire with low alkali or have no alkali.Three is the Chan which choose to useaccommodation with anticipate to repress an alkali bone to anticipate reaction.Because the concrete sprinkle to build, flap Dao bad perhaps is a reinforcing bar protection layer thinner, the harmful material get into concrete to make reinforcing bar creation rust eclipse, the reinforcing bar physical volume of the rust eclipse inflation, cause concrete bulge crack, the crack of this kind type much is a crack lengthways, follow the position of reinforcing bar ually of prevent measure from have:One is assurance reinforcing bar protection the thickness of the layer.Two is a concrete class to go together with to want good.Three is a concrete to sprinkle to note and flap Dao airtight solid.Four is a reinforcing bar surface layer Tu2 Shua antisepsis coating.Crack processingThe emergence of the crack not only would influence structure of whole with just degree, return will cause the rust eclipse of reinforcing bar, acceleration concrete of carbonization, lower durable and anti- of concrete tired, anti- Shen ability.Therefore according to the property of crack and concrete circumstance we want differentiation to treat, in time processing, with assurance building of safety usage.The repair measure of the concrete crack is main to have the following some method:Surface repair method, infuse syrup, the Qian sew method, the structure reinforce a method, concrete displacementmethod, electricity chemistry protection method and imitate to living from heal method.Surface repair the method be a kind of simple, familiar of repair method, it main be applicable to stability and to structure loading the ability don't have the surface crack of influence and deep enter crack of processing.The processing measure that is usually is a surface in crack daubery cement syrup, the wreath oxygen gum mire or at concrete surface Tu2 Shua paint, asphalt etc. antisepsis material, at protection of in the meantime for keeping concrete from continue under the influence of various function to open crack, usually can adoption the surface in crack glue to stick glass fiber cloth etc. measure.1, infuse syrup, the Qian sew methodInfuse a syrup method main the concrete crack been applicable to have influence or have already defend Shen request to the structure whole of repair, it is make use of pressure equipments gum knot the material press into the crack of concrete, gum knot the material harden behind and concrete formation one be whole, thus reinforce of purpose.The in common use gum knot material has the cement the syrup, epoxy, A JiC Xi sour ester and gather ammonia ester to equalize to learn material.The Qian sew a method is that the crack be a kind of most in common use method in, it usually is follow the crack dig slot, the Qianfill Su in the slot or rigid water material with attain closing crack of purpose.The in common use Su material has PVC gum mire, plastics ointment, the D Ji rubber etc.;In common use rigid water material is the polymer cement sand syrup.2, the structure reinforce a methodWhen the crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure.The structure reinforce medium in common use main have the following a few method:The piece of enlargement concrete structure in every aspect accumulate, outside the Cape department of the Gou piece pack type steel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete compensation reinforce.3, concrete displacement methodConcrete displacement method is processing severity damage concrete of a kind of valid method, this method be first will damage of the concrete pick and get rid of, then again displacement go into new of concrete or other material.The in common use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup.ConclusionThe crack is widespread in the concrete structure existence of a kind of phenomenon, it of emergence not only will lower the anti- Shen of building ability, influence building of usage function, and will cause the rust eclipse of reinforcing bar, the carbonization of concrete, lower the durable of material, influence building ofloading ability, so want to carry on to the concrete crack earnest research, differentiation treat, adoption reasonable of the method carry on processing, and at under construction adopt various valid of prevention measure to prevention crack of emergence and development, assurance building and Gou piece safety, stability work.From《CANADIAN JOURNAL OF CIVIL ENGINEERING》。
岩土力学英文版
岩土力学英文版IntroductionGeotechnical Engineering, also known as Soil Mechanics or Rock Mechanics, is a branch of civil engineering that deals with the behavior of soil and rock materials under various conditions. It is an important field of study as it helps engineers understand the properties and characteristics of these materials, which in turn enables them to design and construct safe and stable structures.Soil MechanicsSoil Mechanics is the study of the behavior of soil materials, including its formation, classification, and properties. Various aspects of soil mechanics are essential in geotechnical engineering, such as soil compaction, permeability, and soil stability.Soil formation is a complex process that involves the weathering and erosion of existing rocks, resulting in the formation of different soil types. The composition and particle size distribution of soil influence its properties, including its bearing capacity, shear strength, and compressibility.Soil classification is an important step in understandingthe behavior of various soil types. The Unified Soil Classification System, which categorizes soils based on their particle size and organic content, is widely used in geotechnical engineering. Common soil types include gravel, sand, silt, clay, and organic soils.Understanding soil properties is crucial in determining its suitability for construction projects. Soil compaction refers to the process of densifying soil by applying mechanical force, ensuring stability and reducing settlement. Permeability is the ability of soil to transmit fluids such as water or gas, which is essential in designing drainage systems.Shear strength is another critical property of soil, as it determines its ability to resist sliding or deformation. Soil stability can be assessed through various laboratory tests, such as direct shear tests or triaxial tests, which simulate the conditions that soil experiences in real-world applications.Rock MechanicsRock Mechanics, on the other hand, is the study of the behavior of rock materials, including its strength, deformation, and stability. It plays a crucial role in thedesign and construction of underground structures, such as tunnels and mines, as well as in slope stability analysis. Rock strength is an essential characteristic to consider when designing structures in rock formations. Different rock types have varying strength properties, with factors such as mineral composition, rock structure, and geological history influencing their behavior. Lab testing, such as uniaxial compression tests or point load tests, is typically conducted to determine the rock's strength. Rock deformation refers to the response of rock materials to applied stresses, including compression, tension, and shear. Understanding the deformation behavior of rock is crucial in predicting stability and designing support systems for underground excavations.Slope stability analysis is a critical aspect of geotechnical engineering, especially in hilly or mountainous regions. An unstable slope can lead to landslides or slope failures with disastrous consequences. Various methods, including limit equilibrium analysis and numerical modeling, are used to assess slope stability and design appropriate reinforcement measures.ConclusionGeotechnical engineering plays a vital role in the construction industry as it helps design safe and stable structures by understanding the behavior of soil and rock materials. Soil mechanics focuses on the properties and characteristics of soil, including its formation, classification, and behavior under various conditions. Rock mechanics, on the other hand, studies the properties of rock materials such as strength, deformation, and stability. These fields of study are essential for engineers to ensure the safety and integrity of construction projects.。
【设计】土木工程毕业设计英语论文及翻译
【关键字】设计土木工程毕业设计英语论文及翻译篇一：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 place during 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, theconcrete 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, masoy, 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 verywidely 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 instrength 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 ueinforced 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.篇二：土木工程毕业设计中英文翻译附录：中英文翻译英文部分：LOADSLoads that act on structures are usually classified as dead loads or live loads.Dead loads are fixed in location and constant in magnitude throughout the life of the ually the self-weight of a structure is the most important part of the structure and the unit weight of the material.Concrete density varies from about 90 to 120 pcf (14 to 19 KN/m2)for lightweight concrete,and is about 145 pcf (23 KN/mKN/m2)for normal concrete.In calculating the dead load of structural concrete,usually a 5pcf (1 )increment is included with the weight of the concrete to account for the presence of the 2 reinforcement.Live loads are loads such as occupancy,snow,wind,or traffic loads,or seismic forces.They may be either fully or partially in place,or not present at all.They may also change in location.Althought it is the responsibility of the engineer to calculate dead loads,live loads are usually specified by local,regional,or national codes and specifications.Typical sources are the publications of the American National Standards Institute,the American Association of State Highway and Transportation Officials and,for wind loads,the recommendations of the ASCE Task Committee on Wind Forces.Specified live the loads usually include some allowance for overload,and may include measures such as posting of maximum loads will not be exceeded.It is oftern important to distinguish between the specified load,and what is termed the characteristic load,that is,the load that actually is in effect under normal conditions of service,which may be significantly less.In estimating the long-term deflection of a structure,for example,it is the characteristic load that is important,not the specified load.The sum of the calculated dead load and the specified live load is called the service load,because this is the maximum load which may reasonably be expected to act during the service resisting is a multiple of the service load.StrengthThe strength of a structure depends on the strength of the materials from which it is made.Minimum material strengths are specified in certain standardized ways.The properties of concrete and its components,the methods of mixing,placing,and curing to obtain the required quality,and the methods for testing,are specified by the American Concrete Insititue(ACI).Included by refrence in the same documentare standards of the American Society for Testing Materials(ASTM)pertaining to reinforcing and prestressing steels and concrete.Strength also depends on the care with which the structure is built.Member sizes may differ from specified dimensions,reinforcement may be out of position,or poor placement of concrete may result in voids.An important part of the job of the ergineer is to provide proper supervision of construction.Slighting of this responsibility has had disastrous consequences in more than one instance.Structural SafetySafety requires that the strength of a structure be adequate for all loads that may conceivably act on it.If strength could be predicted accurately and if loads were known with equal certainty,then safely could be assured by providing strength just barely in excess of the requirements of the loads.But there are many sources of uncertainty in the estimation of loads as well as in analysis,design,and construction.These uncertainties require a safety margin.In recent years engineers have come to realize that the matter of structural safety isprobabilistic in nature,and the safety provisions of many current specifications reflect this view.Separate consideration is given to loads and strength.Load factors,larger than unity,are applied to the calculated dead loads and estimated or specified service live loads,to obtain factorde loads that the member must just be capable of sustaining at incipient failure.Load factors pertaining to different types of loads vary,depending on the degree of uncertainty associated with loads of various types,and with the likelihood of simultaneous occurrence of different loads.Early in the development of prestressed concrete,the goal of prestressing was the complete elimination of concrete ternsile stress at service loads.The concept was that of an entirely new,homogeneous material that woukd remain uncracked and respond elastically up to the maximum anticipated loading.This kind of design,where the limiting tensile stressing,while an alternative approach,in which a certain amount of tensile amount of tensile stress is permitted in the concrete at full service load,is called partial prestressing.There are cases in which it is necessary to avoid all risk of cracking and in which full prestressing is required.Such cases include tanks or reservious where leaks must be avoided,submerged structures or those subject to a highly corrosive envionment where maximum protection of reinforcement must be insured,and structures subject to high frequency repetition of load where faatigue of the reinforcement may be a consideration.However,there are many cses where substantially improved performance,reduced cost,or both may be obtained through the use of a lesser amount of prestress.Full predtressed beams may exhibit an undesirable amount of upward camber because of the eccentric prestressing force,a displacement that is only partially counteracted by the gravity loads producing downward deflection.This tendency is aggrabated by creep in the concrete,which magnigies the upward displacement due to the prestress force,but has little influence on the should heavily prestressed members be overloaded and fail,they may do so in a brittle way,rather than gradually as do beams with a smaller amount of prestress.This is important from the point of view of safety,because suddenfailure without warning is dangeroud,and gives no opportunity for corrective measures to be taken.Furthermore,experience indicates that in many cases improved economy results from the use of a combination of unstressed bar steel and high strength prestressed steel tendons.While tensile stress and possible cracking may be allowed at full service load,it is also recognized that such full service load may be infrequently applied.The typical,or characteristic,load acting is likely to be the dead load plus a small fraction of the specified live load.Thus a partially predtressed beam may not be subject to tensile stress under the usual conditions of loading.Cracks may from occasionally,when the maximum load is applied,but these will close completely when that load is removed.They may be no more objectionable in prestressed structures than in ordinary reinforced.They may be no more objectionable in prestressed structures than in ordinary reinforced concrete,in which flexural cracks alwaysform.They may be considered a small price for the improvements in performance and economy that are obtained.It has been observed that reinforced concrete is but a special case of prestressed concrete in which the prestressing force is zero.The behavior of reinforced and prestressed concrete beams,as the failure load is approached,is essentially the same.The Joint European Committee on Concrete establishes threee classes of prestressed beams.Class 1:Fully prestressed,in which no tensile stress is allowed in the concrete at service load.Class 2:Partially prestressed, in which occasional temporary cracking is permitted under infrequent high loads.Class 3:Partially prestressed,in which there may be permanent cracks provided that their width is suitably limited.The choise of a suitable amount of prestress is governed by a variety of factors.These include thenature of the loading (for exmaple,highway or railroad bridged,storage,ect.),the ratio of live to dead load,the frequency of occurrence of loading may be reversed,such as in transmission poles,a high uniform prestress would result ultimate strength and in brittle failure.In such a case,partial prestressing provides the only satifactory solution.The advantages of partial prestressing are important.A smaller prestress force will be required,permitting reduction in the number of tendons and anchorages.The necessary flexural strength may be provided in such cases either by a combination of prestressed tendons and non-prestressed reinforcing bars,or by an adequate number of high-tensile tendons prestredded to level lower than the prestressing force is less,the size of the bottom flange,which is requied mainly to resist the compression when a beam is in the unloaded stage,can be reduced or eliminated altogether.This leads in turn to significant simplification and cost reduction in the construction of forms,as well as resulting in structures that are mor pleasing esthetically.Furthermore,by relaxing the requirement for low service load tension in the concrete,a significant improvement can be made in the deflection characteristics of a beam.Troublesome upward camber of the member in the unloaded stage fan be avoeded,and the prestress force selected primarily to produce the desired deflection for a particular loading condition.The behavior of partially prestressed beamsm,should they be overloaded to failure,is apt to be superior to that of fully prestressed beams,because the improved ductility provides ample warning of distress.英译汉：荷载作用在结构上的荷载通常分为恒载或活载。
岩土工程外文翻译--先进值方法在斜坡稳定性分析中的应用和限制
学生毕业设计（论文）外文译文在市场上可买到的极限平衡的计算机代码在近几年已经有了很大的进步。
这包括：有限元法和地下水应力分析(如GEO-SLOPE’s SIGMA/W, SEEP/W 和 SLOPE/W(6))的二维极限平衡法编码的集成。
三维极限平衡法的发展(例如 CLARA (7); 3D-SLOPE(8))。
概率极限平衡技术的发展。
允许多样的支持和加固的能力。
非饱和土抗剪强度标准的混合。
可视化的高度发展和前处理及后处理的制图学。
这些编码在土坡和高度蚀变岩斜坡的分析中起着至关重要的作用。
而在这些斜坡中，离散明确的表面容易发生滑动。
图2阐明了高岭土化的花岗岩斜坡崩塌的反分析法中的二维极限平衡程序的运用。
包括岩块内部的应力状态和复杂变形及脆性断裂影响是极其重要的。
数值模拟技术也应用其中。
(如图2所示).图 1. SWEDGE 分析(右)建立在DIPS立体图输入的基础上(LEFT).图 2. 用极限平衡法对瓷土边坡进行分析来寻求滑动平面（左）和有线差分来模拟剪应变发展（右）石雨模拟器是另一分析法的传统模式，其中包括用来评估单个坠落方块的危害的工具。
像ROCFALL (2) 的程序用来分析从给定坡面几何上滚动或弹动的岩块在速率发生变水特征; 原位应力状态料、间断运行和液压机械及动态分析)；能够评估不稳定性参数变化的影响样；需要注意缩放效果；需要模拟典型间断几何(间距, 持久性等等)；节理特性可使用的的数据有限(例如jkn, jks).混合物/耦合模拟列出独立模型的输入参数的组合耦合有限元/离散单元模型能够模拟节理和层状媒介上的完整的裂缝延伸和断裂复杂问题需要高端内存容量；在实践中相对来说有较少的经验；需要持续校准和限制连续统建模连续统建模最适合应用于由大量完整岩石、软弱岩石、类土或严重断裂的岩块构成的斜坡。
大多数连续统代码有含离散断裂的设备，如断层和层面。
但是不适用于不均介质的分析。
石坡稳定性中的连续统方法包括有线差分法和有限元素法。
岩土工程 英语论文
UNIVERSITY OF SOUTH CHINACollege:The College of Civil EngineeringName:Fanhua Jiang(姜繁华)Class: Class 2, Grade 2011,Geotechnical EngineeringNo.:20114680213Geotechnical EngineeringWe human have lived in this world for almost hundreds of millions of years. The land of the earth is what human need to live on. We farm on it, graze on it, live on it. And our ancestor has built their houses according to their living experiences, which can reflect our ancestor’s intelligence. The Egypt has pyramid, the India has Taj Mahmal, the Ancient Babylon has Garden in The Air and our China has the Great Wall, etc. As one of the Four Great Ancient Civilizations our ancestor had almost completed the technique of pile foundation in the Ming dynasty. Pile foundation is one of our works and it is the foundation of stability of building. The Leaning Tower of Pisa is one of the remarkable pile foundation works. When it was built, the engineers couldn’t make sure of the condition of the soil under the ground. By the improvement of the technique, the scientists and engineers pay increasingly attention to the geotechnical engineering. Nowadays, we have a lot of ways to test the conditions of the soil to guarantee the buildings’security and safety. During the time of Anti-Japanese War, our army took tactics of tunnel warfare, it also shows the Chinese intelligence of architectural design.Geotechnical engineering is one of the branches of the civil engineering. By contrast, the other subjects are easier to master, somany are not willing to take this as their major. Though this major is so arduous and it seems not in popular demand, I still think it has the most potential to develop. When we see many buildings being built in our city, we should not just notice the outside of these buildings, we should see through the appearance to the essence, the footing of these buildings is vital to the building. The significance of the footing means the most challenging works of all the construction. Before the footing construction, the condition of the underground is invisible, so before we start our works, we have to use high-tech as well as our experience to analyze if the soil is suitable to use or not. In addition, we can also apply our knowledge to the construction of the subway tunnel etc. China, as a developing country, still has to do lots of engineering project, the geotechnical engineer must be the most indispensable person in this field.Because of the work environment, in our college it becomes the most unwelcome major. But we are very proud that the teachers here are very qualified and have a breadth of knowledge. Above all, employment rate of this major is higher and higher, the technique also plays an increasingly important role in our national infrastructure projects and military construction. So we have to advertise our major positively to eliminate the negative message of our major. As a student of USC we also have to form a good attitudetowards study. Only in this way can we be more competitive than others when we graduate.。
岩土专业英语论文7
Design Charts for Piles Supporting Embankmentson Soft ClayH.G.Poulos,F.ASCE1Abstract:This paper describes the development and application of design charts for piled embankment designs.It outlines the compu-tational approach adopted,the geotechnical profiles used,and the application of the design procedure using the charts.The soil profile used for the charts is representative of a Malaysian soft clay profile,involving a more or less normally consolidated soil,with a strength and stiffness that varies linearly with depth.Such a profile is typical of the ground conditions in a variety of countries in the Southeast Asian region.The design charts address the issues of pile capacity,settlement due to embankment load,settlement due to a temporary piling construction platform,and lateral response of piles near the edge of the embankment.The charts consider variations in ground conditions,embankment height,pile length,and pile spacing.An illustrative example is given to demonstrate the use of the charts.DOI:10.1061/͑ASCE͒1090-0241͑2007͒133:5͑493͒CE Database subject headings:Embankments;Foundation design;Lateral displacement;Pile foundations;Settlement;Soil settlement;Clays;Soft soils.IntroductionPiled embankments provide a possible solution for the construc-tion of roads and transport corridors over soft soils.They have the advantage of being relatively rapid to construct and do not require the extended time periods that many conventional forms of ground improvement demand͑e.g.,preloading͒.Piled embank-ments have been used increasingly in a number of regions,includ-ing Europe,Southeast Asia,and Australasia.A variety of methods of design have developed,ranging from relatively simplistic approaches͑for example,British Standards Institution1995͒to relatively sophisticated methods involving advanced numerical analysis͑e.g.,Russell and Pierpoint1997;Kempton et al.1998; Hsi2001;Han and Gabr2002;Wong2002͒.The majority of the simpler methods address only the stability or ultimate limit state, or else focus on the issue of load sharing and arching between the piles and the ground͑e.g.,Ting and Toh1983;Hewlett and Randolph1988;Low et al.1994͒.The simpler design methods currently available give little or no consideration to settlements and deformations.In many cases, such deformations may have a profound influence on the long-term performance of the embankment,and design criteria fre-quently specify upper limits to the values of settlement and differential settlement that can be tolerated.While advanced nu-merical analyses may be appropriate and necessary for detailed design,they are generally not suited to a rapid assessment of the feasibility of piled embankment construction for a particular site.To facilitate preliminary assessment and design of piled em-bankments,a series of design charts has been developed.The charts consider variations in ground conditions,embankment heights,and pile types.For simplicity,a perfectlyflexible em-bankment has been assumed.Consideration is also given to the effects of soil movements arising from the construction of a tem-porary piling platformfill͑typically1to1.5m thick͒.The soil profile used for the charts is representative of a Ma-laysian soft clay profile,involving a more or less normally con-solidated soil,with a strength and stiffness that varies linearly with depth.Such a profile is typical of the ground conditions in a variety of countries in the Southeast Asian region.This paper describes the development and application of the design charts for piled embankment designs.It outlines the com-putational approach adopted,the geotechnical profiles used,and the application of the design procedure using the charts.Illustra-tive examples are given to demonstrate the use of the charts. Geotechnical ModelA considerable amount of information on the geotechnical char-acteristics of soft marine clay deposits in Malaysia is available ͑e.g.,Ramli et al.1994;Ramli and Ismael,personal communica-tion,1992;Sagae and Goh1997;Tan et al.2004͒.There is anindication that,below a surface desiccated crust2–3m thick,the clays are more or less normally consolidated and have an und-rained shear strength that increases linearly with depth.On the basis of the available data,the relationship chosen for the present study is represented by the relationships u=10+1.5z kPa͑1͒where zϭdepth below the soil surface͑m͒.This relationship is perhaps more conservative than that sug-gested by Ramli et al.͑1994͒and is towards the lower end of the range of values given by Tan et al.͑2004͒,but appears to be a reasonable͑albeit conservative͒fit to the data.1Senior Principal,Coffey Geotechnics;and,Professor Emeritus,Univ. of Sydney,8/12Mars Rd.,Lane Cove West,NSW,Australia2066. E-mail:harry-poulos@.auNote.Discussion open until October1,2007.Separate discussions must be submitted for individual papers.To extend the closing date by one month,a written request must befiled with the ASCE Managing Editor.The manuscript for this paper was submitted for review and pos-sible publication on September2,2005;approved on June28,2006.This paper is part of the Journal of Geotechnical and Geoenvironmental Engineering,V ol.133,No.5,May1,2007.©ASCE,ISSN1090-0241/ 2007/5-493–501/$25.00.For the estimation of settlements due to surface loadings,datafrom the available references was examined,and values adoptedfor the compression ratio͓C c/͑1+e0͔͒in the upper15m were 0.30for the normally consolidated state and0.05for the overcon-solidated state.Below15m,the compression ratio was taken tobe0.15for the normally consolidated state and0.025for theoverconsolidated state.It is understood that the lower compres-sion ratio below15m may be a consequence of this soil having alower water content,plasticity index,and liquidity index than thesoil above it.The upper5m was assumed to be overconsolidated,with the remainder of the soil profile being normallyconsolidated.For the estimation of pile settlements,it was assumed that theembankment piles would be driven,and account was taken of theeffects of pile installation in stiffening the soil around the drivenpiles.Based on correlations developed by Poulos͑1972͒for softclays,a drained Young’s modulus of the soil around the pile of300s u was adopted for the design charts.Consideration is givenhere only to the long-term settlements of the embankment,whichinclude both undrained and consolidation components,but ex-cluding any long-term creep settlements.For estimation of pile capacity,the ultimate skin friction wasrelated to the undrained shear strength via the adhesion factor␣,which is itself a function of s u͑Tomlinson1986͒.The value of␣was typically within the range0.9–1.0.The ultimate base resis-tance was taken as9s ub,where s ubϭundrained shear strength in the vicinity of the pile tip.For the purposes of the design charts,the basic value of the total thickness of the soft clay layer was taken to be40m,but the effects of shallower layer depths were also investigated and ex-pressed in terms of correction factors to the results for the40-m layer depth.Underlying the soft clay is a layer of stiff clay,whose properties were assessed from data presented by Ramli et al.͑1994͒.It is recognized that the chosen soil profile is rather spe-cific and that the influence of such important factors as stress history,stratigraphy,and soil properties are not incorporated into this study.Nevertheless,it is felt that the charts may provide a reasonable indication of the design requirements for piles sup-porting embankments on relatively thick deposits of clay that are essentially normally consolidated.Fig.1summarizes the geotechnical model adopted for the de-velopment of the design charts.Development of Design ChartsThe design of piles for piled embankments requires consideration of at least four issues:•Geotechnical capacity of the piles;•Settlement of the piles;•Lateral response of the piles;and•Structural capacity of the piles.For the purposes of developing design charts,attention here is focused on thefirst two issues,but some consideration is also given to the other two.If the pile heads are properly attached to a slab or mattress,then lateral pile deflections should not be a con-cern unless ground movements are generated by some other ac-tivity adjacent to the piles,e.g.,filling or excavation.Such effects are examined in this paper.The axial forces for structural design of the piles should include both those arising from the applied loading and the downdrag forces developed by ground move-ments due to the placement offill for a piling platform.Consid-eration is also given to these downdrag forces here.Analysis ProcedureThe main analyses were carried out to obtain three aspects of the behavior of embankment piles:1.The axial load-settlement behavior,including the ultimateaxial load capacity and the single pile head stiffness;2.The effect of group interaction on pile head stiffness;and3.The effect on the piles of vertical ground movements inducedby the construction of thefill for the piling platform͑the possible effects of lateral ground movements were not considered͒.For these analyses,two computer programs were used:PIES͑for Items1and3above͒and DEFPIG͑for Item2͒.Both programs were developed at the University of Sydney,Australia.PIES computes the axial movement and load distribution within a pile subjected to axial load and/or externally imposed vertical soil movements.The program uses a simplified boundary element formulation,and the soil can be represented either by an elastic continuum or a series of springs.In each case,nonlinear response of the interface can be incorporated by assuming an elastic-plastic or hyperbolic relationship between soil stiffness and stress level,and by allowing for the effects of pile-soil slip and base bearing failure by specifying limiting values of shaft resistance and end-bearing resistance.DEFPIG is a program for calculating the deformations and load distribution within a group of piles subjected to vertical, horizontal,and moment loading.The program considers a group of identical elastic piles having axial and lateral stiffnesses that are constant with depth.The piles may be vertical or raked.The piles are supported by a linear elastic continuum,but the program allows for the possibility of slippage between the soil and the piles under axial loading,and the development of yield of the soil adjacent to the pile due to lateral loading.Thus,load-deformation relationships to failure may be obtained.Pile-soil-pile interaction within the group is taken into account via interaction factors that can be computed by the program or input as data.Nonhomoge-neity of the soil along the pile can be taken into account in an approximate manner.The above programs were used in the followingmanner:Fig.1.Assumed geotechnical profile•PIES was used to obtain the nonlinear pile head stiffness of a single isolated pile;the stiffness was related to the applied load level.PIES was also used to obtain the pile head settlement and downdrag load in the pile due to vertical ground settlement.•DEFPIG was used to estimate the effect of pile-soil-pile inter-action on the pile head stiffness,via a group settlement ratio.Ranges of Parameters ConsideredThe basic problem addressed is illustrated in Fig.2.For the de-sign charts developed,the following ranges of parameters have been considered:•Embankment height h e :2,3,4,5m;•Pile size b :250,300mm ͑square precast concrete piles ͒,but attention is focused on 300-mm piles;•Pile length L :10,14,20,24,30,34,40m;•Pile center-to-center spacing:s =2.5,3.0,3.5m;and •Layer depth h :10,20,30,40m.The effect of the fill for the piling platform on pile capacity and stiffness was ignored.Also,the embankment heights listed above are over and above the thickness of the fill for the piling platform.For a single pile,the load-settlement behavior was computed from the PIES analysis.A hyperbolic interface stiffness has been assumed,with hyperbolic parameters of 0.25for the shaft and 0.5for the pile base ͑Poulos 1989͒,since such values are found to give load-settlement curves that are in reasonable agreement with the results of a number of load tests on single piles.In the assess-ment of group interaction,it has been assumed that interaction beyond a spacing of 25pile widths is negligible.Account has been taken of the presence of the soft,normally consolidated clay below the pile tips.In order to take some account of the realities of pile installation ͑purely on the basis of judgment ͒,it has been assumed that installation of a group of piles will affect the stiff-ness of the soil to a depth of approximately 10single-pile widths below the tips.In this region,the soil is assumed to be overcon-solidated.Beyond this depth,the soil modulus is assumed to be unaffected by pile installation,and is that for the normally con-solidated clay.This value has been estimated from the normally consolidated compression ratio for the clay.Ground settlements due to the piling platform will depend on the amount of fill placed,the extent of the fill,and the time between fill placement and the installation of the piles.To simplify the calculations,it has been assumed that the ground settlement decreases linearly with depth,from a maximum at the surface to zero at the top of the stiff clay ͑at 40m depth ͒.Themaximum surface settlement used for the PIES analysis was 1.0m,which is approximately the total settlement computed for a 1.3-m thick fill platform.Design ChartsThe design charts developed for the design of the piles are shown in Figs.3–11,and are described below.Ultimate Axial Load CapacityFig.3shows the computed axial load capacity as a function of pile length,for the two pile sizes considered.The piles are as-sumed to act as friction piles for pile lengths less than 40m.As is obvious,the ultimate capacity increases with increasing pile length and pile size.Axial Stiffness of Single PilesThe axial pile head stiffness of a single pile,K v 1,can be ex-pressed asfollows:Fig.2.Definition of parameters for designchartsFig.3.Ultimate axial capacity versus pile lengthK v 1=K 40F kh͑2͒where K 40ϭpile stiffness for 40-m thick soft clay layer,and F kh ϭcorrection factor for effect of layer depth.K 40is shown in Fig.4for the 300-mm piles,and is plotted against pile length for various values of applied load.Clearly,higher loads can only be sustained by the longer piles.K 40in-creases with increasing pile length,but decreases as the pile load increases.A similar chart could be developed for other pile sizes,and for 250-mm piles,for example,the computed stiffness values are about 15–20%less than those for a 300-mm pile.F kh is plot-ted in Fig.5as a function of the thickness of the soft clay layer,for various pile lengths.This factor increases with increasing pile length or decreasing layer depth.Group Settlement RatioThe group settlement ratio R s can be expressed as follows:R s =R 40F Rh͑3͒where R 40ϭsettlement ratio for 40-m layer depth,and F Rh ϭcorrection factor for layer depth.Fig.6presents computed values of the group settlement ratio R 40,for 300-mm piles within the interior of a large group.The settlement ratio is the ratio of the group settlement to the settle-ment of a single pile,at the same average load per pile.R 40is not very sensitive to load level,and these plots have been prepared for a load of 250kN to simplify presentation.R 40decreases with increasing pile length and with increasing pile spacing.Fig.7shows the correction factor F Rh ,which decreases as the layerdepth decreases,i.e.,there is less interaction among the piles for shallower layer depths.Pile length also has some influence on F Rh .It will be noted that the computed settlement ratios are very large,due primarily to the presence of the soft clay below the piles and the consequent increase in pile interaction compared to the case of homogeneous stiffclay.Fig.4.Axial stiffness of single 300-mm precastpilesFig.5.Correction factor for effect of clay layer thickness on single pilestiffnessFig.6.Group settlement ratio for 300-mm precast pilesThe stiffness of a pile in a group environment K g can be cal-culated as follows:K g =K v 1/R s =K 40F kh /͑R 40F Rh ͒͑4͒where K v 1ϭstiffness of single isolated pile,and R s ϭsettlement ratio,as defined in Eqs.͑2͒and ͑3͒.Effect of Pile Position on Group Settlement Ratio The results in Figs.6and 7are for piles within the interior of a large group.For piles near the edge of an embankment,the pile interaction will differ from that for the interior piles because the outer piles have different loads than the interior piles ͑because of the embankment slope ͒and also because,near the embankment toe,there are fewer piles involved in the interaction process.Calculations have been carried out to assess the effect of the position of a pile on the group settlement ratio.A “pile position factor”f p has been developed from analyses of a piled strip,using the computer program GASP ͑Poulos 1991͒.These factors have been derived for the typical case of a concrete slab 0.4-m thick over the piles,and are given in Table 1.These factors are approxi-mate,and have been computed for a spacing of 3.5m,but may beapplied as a first approximation for the other spacings considered here.The stiffness of a pile in the group,allowing for pile position,is then given byK g =K v 1f p /R s =K 40F kh f p /͑R 40F Rh ͒͑5͒Settlement ChartsBased on the results presented above,the settlement S g of a pile in a group supporting an embankment can be expressed as follows:S g =␥h e s 2R s /K v 1f p =␥h e R 40F Rh /͑K 40f p F kh ͒͑6͒where ␥ϭunit weight of embankment fill,h e ϭheight of embank-ment fill above the pile in question,s ϭcenter-to-center spacing of piles,and R s ,K v 1,R 40,F Rh ,K 40,F kh ,and f p are as defined above.The results in Figs.3–7may be used with this equation to calculate the settlement of piles beneath embankments of various heights,for different spacings.Fig.8shows the results of such calculations,for embankment heights between 2m and 5m,and for a soft soil layer depth of 40m,assuming that the unit weight of the embankment fill is 20kN/m 3.The results in these figures are for interior piles,i.e.,the position factor f p is 1.0.As might be expected,settlement decreases as the pile length increases or the pile spacing decreases.For the higher embankments,it will not be feasible to use some combinations of pile size,pile length,and pile spacing,as the factor of safety against axial failure of the piles will not be adequate.Fig.8provides a convenient means of estimating the settle-ment of a piled embankment due to embankment loading,once a pile length has been selected to satisfy ultimate capacity require-Table 1.Pile Position Factor f p Pile locationPosition factor f pOuter row ͑nearest to embankment toe ͒ 1.43Second row 0.81Third row 0.90Fourth row 0.96Inner rows1.0Fig.7.Correction factor for effect of layer depth on group settlementratioFig.8.Settlement charts for interior 300-mm precast pilesments.As a rough approximation,where such capacity require-ments are satisfied,the results in Fig.8can be approximated as follows:S g Ϸ͑0.540−0.016L +0.0001L 2͒␥h e s 2͑7͒where S g is in mm,and L ϭpile length ͑m ͒.It should,however,be noted that to this settlement caused by embankment loading,the settlement of the piles due to any ground settlements should be added.These settlements are dis-cussed below.Pile Head Settlement due to Ground Settlement As mentioned previously,ground settlements will occur as a con-sequence of the placement of fill for the piling platform.When subjected to ground settlement,a pile will generally settle less than the ground surface.The ratio of the pile head settlement to the ground surface settlement,,is plotted in Fig.9as a function of the pile length and the soil layer depth.decreases as the pile length increases,and as the layer depth h decreases.is more or less independent of pile size,as has also been found by Poulos ͑1989͒.The pile head settlement,S ps ,due to ground settlement can then be simply calculated asS ps =S 0͑8͒where S 0ϭground surface settlement arising from the fill for the piling platform,and ϭground settlement factor.Downdrag Force in PileThe computed downdrag force in a pile will depend on the amount of ground settlement.However,it is found that for surface settlements in excess of about 300mm,full slip occurs between the pile shaft and the soil,and a limiting downdrag force is then generated in the pile.Pile group effects may also affect the de-velopment of downdrag force,and there is a tendency for group effects to reduce the settlement and downdrag force developed in a pile.However,for relatively large surface settlements,and rela-tively wide pile spacings ͑such as the case here ͒,the downdrag force in a pile within a group will be little different from that in a single isolated pile.Thus,no allowance has been made for group effects or pile position.Fig.10plots this limiting downdrag force as a function of pile length,for a soft soil layer depth of 40m.The downdrag force increases as the pile length or pile size increases,and can reach relatively large values for piles in excess of 30m or so.For layers less than 40m depth,the maximum downdrag force will be al-most the same as that for a 40m layer,unless the pile tip rests on the stiffer clay layer.The maximum downdrag force in that case is increased,typically by between 30and 50kN for 250-mm piles,and 40to 70kN for 300-mm piles.It should be noted that the axial force in the piles will have components due both to the applied embankment loading and the downdrag arising from ground movements.The maximum value from embankment loading occurs at the pile head,while the maximum due to downdrag occurs lower down the pile ͑typically at about 2/3of the pile length ͒.Thus,the maximum axial load will be less than the sum of the maxima of the two components;i.e.,it will be conservative to add the axial load due to the em-bankment and the maximum downdrag force.A more refined analysis can be carried out if it is found that the sum of the maxima is close to the structural capacity of the piles.Other Design IssuesTransition Areas between Embankments of Varying HeightThe embankment height will generally vary in two circumstances:•Transversely across the embankment where the height willde-Fig.9.Factor relating pile head settlement to soil surfacesettlement Fig.10.Maximum downdrag force developed in pile by soil movementcrease from a maximum value at the embankment crest to zero at the toe;and•Longitudinally as the embankment approaches a bridge abut-ment,via a transition zone.In order to control differential settlements in such transition zones,the piles supporting the embankment should be designed to have specified settlements.In order to achieve this,the total settlement S ti of a pile i due to both embankment loading and ground movement can be calculated asS ti=S gi+S psi=␥h ei R s s2/͑K v1i f pi͒+i S o͑9͒=␥h e i R40F rh s2/͑K40i f pi F khi͒+i S o͑9a͒where S giϭsettlement of pile i due to embankment loading;S psiϭsettlement of pile i due to ground settlement;h eiϭheight of embankment above pile i;R40ϭgroup settlement ratio for40-m layer depth͑Fig.6͒;F Rhϭcorrection factor for layer depth͑Fig. 7͒;sϭcenter-to center spacing of piles;K40iϭpile head stiffness for pile i͑if isolated͒͑Fig.4͒;F khiϭcorrection factor for layer depth for pile i͑Fig.5͒;f piϭposition factor for pile i͑Table1͒; andiϭground settlement factor for pile i͑Fig.9͒.By computing S ti for a series of pile lengths,embankment heights,and pile spacings,it is possible to develop a design in which the settlement of the piles under various embankment heights is theoretically within tolerable limits͑as defined by the allowable settlement gradient͒.A very important point emerges from the above results.If the ground surface settlement S0is relatively large,the total settle-ment of the pile will generally be dominated by the component S0due to the ground settlement.The factoris dependent largely on pile length͑see Fig.9͒;hence,if piles of different length are to be used,this component will differ for each pile length.Thus,if equal or nearly equal settlements are required, then it would appear desirable to design the piles to have lengthswhich are equal or nearly equal.Care therefore needs to be exer-cised in order to obtain a design in which the settlements in the various sections satisfy the design requirements.Effect of Lateral Soil MovementsIffill is placed over soft clay to construct a piling platform,lateral soil movements will tend to be developed as well as settlements. While the predominant effect will be a vertical settlement͑see Sec.IV F above͒,the lateral movements may not be negligible near the edges of the platformfiteral ground movements will tend to induce bending moments,shears,and lateral deflections in the embankment piles,and should therefore be considered in the design process.If the profile of lateral ground movement with depth can be assessed,the effects on the piles can be estimated via a lateral pile-soil interaction analysis͑e.g.,Poulos and Davis 1980͒.The case of a longfill platform50wide and1m thick,on a 40-m thick soft clay layer,has been considered.The distributions of lateral displacement at various locations have been computed by an elasticfinite layer analysis.In reality,embankment piles will be installed after thefill platform has been placed,and will therefore be subjected to the consolidation lateral movements,but not the immediate undrained movements caused by thefill.There-fore,in order to obtain more realistic results,the consolidation movements due to thefill have been computed,these being ob-tained as the difference between the totalfinal movements͑using the drained modulus values for the clay͒and the undrained move-ments͑using the undrained modulus values for the clay͒.The lateral drained and lateral undrained modulus values have been taken as80s u and150s u respectively.Fig.11shows computed results for the300-mm piles,and for four different pile head boundary conditions:•Fixed restrained head͑e.g.,pilesfixed rigidly into a thick con-crete slab͒;•Pinned restrained head͑e.g.,piles attached to a concrete slab, but without moment resistance͒;•Fixed unrestrained head;and•Free unrestrained head͑e.g.,piles with individual pile caps below aflexible mattress͒.Thisfigure plots the computed maximum bending moments, pile head deflection and pile head shear,as a function of the distance of the pile from the edge of thefill.The results are for a 40-m long pile in a soft clay layer40-m thick,but apply equally well to pile lengths and soil layer depths in excess of about5m.The following points can be noted:•The moment,shear,and deflection decrease as the pile position moves away from the edge of thefill;•The provision of movement restraint at the pile head results in substantial moments and shears being developed in the piles;and•For piles without head restraint,the bending moments are rela-tively small,but the deflections can be of the order of tens of millimeters,depending on how far the pile is from thefilledge.teral response induced in piles by1-mfill platform, 300-mm pilesFrom this study,two additional design principles emerge in order to reduce the potential moments,shears,and deflections that will be induced in the piles:•It is desirable to extend the platformfill well beyond the last pile;and•Where the embankment is to be supported on a concrete slab, it is preferable to avoidfixing the piles rigidly to the slab. Summary of Design ProcedureThe following step-by-step procedure can be adopted for the de-sign of piled embankments to resist axial loadings:1.From the embankment height,calculate the average pile loadP a v asP a v=␥h e s2͑10͒where␥ϭembankment unit weight,h eϭembankment height,and sϭpile spacing.2.For the specified factor of safety͑FS͒against axial geotech-nical failure,obtain the required ultimate load capacity of the piles asP u=FSP a v͑11͒3.Assess the required combination of pile size and pile lengthto obtain the required ultimate capacity P u,for example, from Fig.3.4.Calculate the settlement of the piles due to the embankmentloading,either by use of Fig.8or Eq.͑7͒͑note that these are for a40-m soft clay layer͒,or alternatively,by use of the following equation:S g=␥h e R40F Rh s2/͑K40f p F kh͒͑12͒For the interior piles,h eϭfull height of the embankment, while for piles near the edge of the embankment,h eϭaverage height of the embankment above the pile.The single pile stiffness and correction factors K40and F kh are obtained from Figs.4and5,the settlement R40from Fig.6,the depth cor-rection factor F rh from Fig.7,and the position factor f p from Table1.5.Calculate the additional settlement of the pile head,S ps,aris-ing from ground settlement,as follows:S ps=S0͑13͒where S0ϭestimated ground surface settlement arising from the piling platformfill,andϭground settlement factor,ob-tained from Fig.9.6.The total pile settlement is S t=S g+S ps,͓see Eq.9͔and thisshould be checked against the allowable settlement specified for design.7.The maximum downdrag force can be readily computed,orelse estimated from Fig.10,and the structural design of the pile should make provision for this force.8.For transition areas,a trial-and-error process can beemployed to evaluate the combinations of pile length,pile spacing,and pile size that give settlements that satisfy the specified differential settlement requirements.This can be achieved by selecting appropriate combinations of pile size, pile length,and pile spacing.9.Consideration should be given to the possible effects of lat-eral ground movements on the piles,especially in terms of induced bending moments.Ideally,thefill platform causing these lateral movements should extend a sufficient distancefrom the embankment toe so that these bending moments are small.This distance can be assessed from Fig.11.10.Design of the concrete slab or reinforced mattress supportingthe embankment should be carried out,using the provisions of a code such as BS8006͑1995͒,or via an analysis that accounts for the slab-pile-soil interaction͑e.g.,Poulos, 1998͒.An illustrative example is presented in the Appendix to illus-trate the application of the design charts to the design of piles for a typical embankment.ConclusionsDesign charts for piles supporting embankments have been de-rived and presented in this report,for a soil profile typical of the soft marine clay deposits in Malaysia.Two commonly used pile sizes have been considered,for a variety of pile lengths and spacings.The charts have addressed the following aspects of pile design:•Ultimate axial load capacity;•Settlement,including group effects and the effect of pile posi-tion below embankment;•Effect of ground settlements such as those arising from the construction of a piling platformfill;and•Effect of lateral ground movements on the piles.A number of important design principles have emerged from this study:•The effects of ground settlements can be very important and can lead to considerable settlement of the piles.•Differential settlement in transition areas can be controlled by designing the embankment piles to have settlements that sat-isfy the specified differential settlement criteria.This can be achieved by selecting appropriate combinations of pile size, length,and spacing.•To avoid excessive effects of lateral ground movements on the piles,the piling platformfill should extend well beyond the edges of the embankment.•To avoid excessive bending moments,shears,and deflections arising fromfill-induced lateral soil movements,thefill plat-form should extend well beyond the last pile,and the pile heads should not befixed rigidly to the supporting slab or mattress.AcknowledgmentsThe work described in this paper was carried out on behalf of Pengurusan Lebuhraya Berhad,Malaysia.The writer acknowl-edges the encouragement of C.W.Lee and M.Kartsounis.The constructive comments of the reviewers are also appreciated,as is the assistance of Maria Domadenik in preparing thefinal manu-script and Annette Wilson in redrafting thefigures. Appendix.Design ExampleDesign of Piles for a2-m EmbankmentIn this example,it will be assumed that a design is required for a 2-m high embankment on the typical soil profile,40m deep,as shown in Fig.1.The geotechnical design criteria are as follows:•A factor of safety of2against ultimate axial failure;and。
岩土工程对生活的影响英语作文
岩土工程对生活的影响英语作文In geotechnical engineering construction, the discharge of pollutants that do not meet the standard will lead to potential threats to the environmental quality and affect the quality and level of engineering construction. Cooling water and slurry drainage are used during drilling or pile construction, which leads to water pollution at the geotechnical construction site and has a great impact on the construction environment. Due to the weak awareness of environmental protection of some construction units and construction personnel and the impact of tight construction period, environmental pollution occurred in the process of using slurry wall protection, which restricted the quality and development level of geotechnical engineering construction. The degree of environmental pollution caused by building materials will gradually increase over time, affecting the realization of geotechnical engineering construction goals.In geotechnical engineering construction, such as the storage and handling process, it is easy to produce more dust, and the pollutants in the atmospheric environment gradually increase, which not only aggravates the degree ofair pollution, poses a potential threat to human health, leaves hidden dangers in geotechnical engineering construction, but also reduces the ecological benefits of geotechnical engineering construction and affects the sustainable development of the construction industry.For the study of geotechnical engineering construction, we need to understand its impact on the ecological environment. During the operation of pile drivers, excavators and other mechanical equipment at the construction site, noise pollution will be generated, which will affect the surrounding environment of geotechnical engineering and cause certain interference to the normal life of residents. After the geotechnical engineering enters the pile excavation construction stage, the original soil balance will be broken, which will affect the surrounding environment and cause pollution problems while reducing the safety of engineering construction. In addition, in the process of promoting the geotechnical engineering construction plan, the random stacking and discarding of relevant wastes will cause environmental pollution. Relevant measures and strategies should be formulated to provide professional support for theefficient construction of geotechnical engineering and the development of construction undertakings, and promote the development of environmental protection undertakings.岩土工程施工作业中，污染物排放不达标会导致环境质量受到潜在威胁，影响工程施工质量和水平。
由城市建设引起的岩土工程问题作文3000
由城市建设引起的岩土工程问题作文3000City development can bring about various geotechnical engineering problems. 城市的建设可能引起各种各样的岩土工程问题。
With the rapid urbanization and increasing population in many cities, there is a growing demand for infrastructure construction. 随着许多城市的快速城市化和人口增长，基础设施建设的需求也在增加。
This often involves the construction of buildings, roads, bridges, and other structures that require extensive geotechnical engineering expertise. 这通常涉及到建筑物、道路、桥梁和其他结构的建设，这需要丰富的岩土工程知识。
However, these developments can also pose significant challenges due to the complex geological conditions and the need for sustainable solutions. 然而，由于复杂的地质条件和对可持续解决方案的需求，这些发展也可能带来重大挑战。
One of the key issues that arise from city development is the risk of foundation failure. 由城市发展引起的一个关键问题是地基失败的风险。
As buildings and structures are constructed on varying soil types, it is essential to conduct site investigations and soil testing to assess the ground conditions. 由于建筑物和结构建在不同类型的土壤上，进行现场调查和土壤测试以评估地面状况至关重要。
关于土木工程英语文章
关于土木工程英语文章Title: The Evolution and Significance of Civil Engineering in the Modern WorldCivil engineering, a discipline that dates back to the ancient civilizations, has been instrumental in shaping the landscape of human settlements and infrastructure. From the pyramids of Egypt to the modern skyscrapers and bridges, the evolution of civil engineering has been remarkable, reflecting the advancements in technology, materials, and design principles.In ancient times, civil engineering was primarily concerned with the construction of basic structures such as temples, palaces, and fortifications. These structures were built using locally available materials like stone, brick, and wood. The Egyptians, for instance, used their knowledge of geometry and hydraulics to construct the pyramids and irrigation systems. Similarly, the Romans excelled in the design and construction of roads, bridges, and aqueducts, which were built to last for centuries.The Industrial Revolution marked a significant turning point in the evolution of civil engineering. With the advent of new materials like steel and concrete, engineers were able to design and build more complex and durable structures. The construction of railways, canals, and dams became commonplace, connecting different parts of the world and enabling economic growth.In the 20th and 21st centuries, civil engineering has undergone further revolutions, particularly with the advent of technology and computing. The use of computers and software has greatly simplified complex calculations and design processes, making it possible to build structures that are safer, more efficient, and sustainable. Additionally, the development of new materials like reinforced concrete, high-strength steel, and composites has further broadened the scope of civil engineering.Modern civil engineers are involved in a wide range of projects, from the design and construction of high-rise buildings and bridges to the development of transportation systems, water supply networks, and environmental engineering solutions. They work closely with architects,planners, and other professionals to ensure that the built environment is not only functional but also aesthetically pleasing and environmentally friendly.The significance of civil engineering in the modern world cannot be overstated. It is crucial for the development of infrastructure, which is essential for economic growth, social progress, and national security. Well-designed and constructed infrastructure can improve the quality of life by providing safe and efficient transportation, clean water, and sanitation facilities. It can also contribute to the resilience of communities in the face of natural disasters and climate change.Moreover, civil engineering plays a vital role in sustainable development. Engineers are increasingly focusing on the use of renewable materials, energy-efficient design, and waste reduction techniques to minimize the environmental impact of construction projects. They are also exploring innovative solutions to address challenges such as urbanization, climate change, and resource scarcity.In conclusion, civil engineering has come a long way from its ancient origins to the sophisticated and complex structures of today. It remains an essential discipline that shapes our world, connecting people, and driving economic and social progress. As technology and society continue to evolve, civil engineering will continue to adapt and innovate, playing a crucial role in building a sustainable and resilient future.。
岩土工程-英语论文
Geotechnical EngineeringGeotechnical engineering is one of the branches of the civil engineering. By contrast, the other subjects are easier to master, so many are not willing to take this as their major. Though this major is so arduous and it seems not in popular demand, I still think it has the most potential to develop. When we see many buildings being built in our city, we should not just notice the outside of these buildings, we should see through the appearance to the essence, the footing of these buildings is vital to the building. The significance of the footing means the most challenging works of all the construction. Before the footing construction, the condition of the underground is invisible, so before we start our works, we have to use high-tech as well as our experience to analyze if the soil is suitable to use or not. In addition, we can also apply our knowledge to the construction of the subway tunnel etc. China, as a developing country, still has to do lots of engineering project, the geotechnical engineer must be the most indispensable person in this field.Because of the work environment, in our college it becomes the most unwelcome major. But we are very proud that the teachers here are very qualified and have a breadth of knowledge. Above all, employment rate of this major is higher and higher, the technique also plays an increasingly important role in our nationalinfrastructure projects and military construction. So we have to advertise our major positively to eliminate the negative message of our major. As a student we also have to form a good attitude towards study. Only in this way can we be more competitive than others when we graduate.。
12 Homework 2012.05.09岩土工程分析
Coulomb yielding criterion for purely frictional materials (tensile stress is positive):
3 1 sin 1 1 sin
1 = xx = -40 kPa
Hence,
1 sin 1 sin 30 zz 3 1 40 120kPa. 1 sin 1 sin 30
401 800 Pi Pi Pi 2Cu 2 50 399 399
Nottingham Centre
for Geomechanics Pi = 49.875 kPa (or 399/8)
Example 2 (d)When the actual internal pressure is only half the yielding value calculated from (c), plot the stress distributions (rr and ) in the soil surrounding the tunnel. Answer: 1 400 a2 If Pi = half of yielding value = 24.9375 kPa, rr 399 Pi 399 Pi r 2 Some points
Pi a 2 Peb 2 Pi Pe a 2b 2 rr b 2 a 2 b 2 a 2 r 2 Pi a 2 Peb 2 Pi Pe a 2b 2 2 2 2 2 2 b a b a r
where: b=20a, Pe=0, r=a
Hale Waihona Puke Nottingham Centre for Geomechanics
土木工程类专业英文文献及翻译
土木工程类专业英文文献及翻译第一篇：土木工程类专业英文文献及翻译PAVEMENT PROBLEMS CAUSEDBY COLLAPSIBLE SUBGRADESBy Sandra L.Houston,1 Associate Member, ASCE(Reviewed by the Highway Division)ABSTRACT: Problem subgrade materials consisting of collapsible soils are com-mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation.Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils.A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented.Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used.INTRODUCTION When a soil is given free access to water, it may decrease in volume,increase in volume, or do nothing.A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil.The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting.Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be-ginning of the professional practice and have cost many millions of dollars in roadway repairs.The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing withthese problem subgrade materials.Each project will have different design considerations, economic con-straints, and risk factors that will have to be taken into account.However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made.For example, typical techniques for dealing with expansive clays include:(1)In situ treatments with substances such as lime, cement, or fly-ash;(2)seepage barriers and/ or drainage systems;or(3)a computing of the serviceability loss and a mod-ification of the design to “accept” the anticipated expansion.In order to make the most economical decision, the amount of volume change(especially non-uniform volume change)must be accurately estimated, and the degree of road roughness evaluated from these data.Similarly, alternative design techniques are available for any roadway problem.The emphasis here will be placed on presenting economical and simple methods for:(1)Determining whether the subgrade materials are collapsible;and(2)estimating the amount of volume change that is likely to occur in the 'Asst.Prof., Ctr.for Advanced Res.in Transp., Arizona State Univ., Tempe, AZ 85287.Note.Discussion open until April 1, 1989.To extend the closing date one month,a written request must be filed with the ASCE Manager of Journals.The manuscriptfor this paper was submitted for review and possible publication on February 3, 1988.This paper is part of the Journal of Transportation.Engineering, Vol.114, No.6,November, 1988.ASCE, ISSN 0733-947X/88/0006-0673/$1.00 + $.15 per page.Paper No.22902.673field for the collapsible soils.Then this information will place the engineerin a position to make a rational design decision.Collapsible soils are fre-quently encountered in an arid climate.The depositional process and for-mation of these soils, and methods for identification and evaluation of theamount of volume change that may occur, will be discussed in the followingsections.COLLAPSIBLE SOILSFormation of Collapsible SoilsCollapsible soils have high void ratios and low densities and are typicallycohesionless or only slightly cohesive.In an arid climate, evaporation greatlyexceeds rainfall.Consequently, only the near-surface soils become wettedfrom normal rainfall.It is the combination of the depositional process andthe climate conditions that leads to the formation of the collapsible soil.Although collapsible soils exist in nondesert regions, the dry environment inwhich evaporation exceeds precipitation is very favorable for the formationof the collapsible structure.As the soil dries by evaporation, capillary tension causes the remainingwater to withdraw into the soil grain interfaces, bringing with it soluble salts,clay, and silt particles.As the soil continues to dry, these salts, clays, andsilts come out of solution, and “tack-we ld” the larger grains together.Thisleads to a soil structure that has high apparent strength at its low, naturalwater content.However, collapse of the “cemented” structure may occurupon wetting because the bonding material weakens and softens, and the soilis unstable at any stress level that exceeds that at which the soil had beenpreviously wetted.Thus, if the amount of water made available to the soilis increased above that which naturally exists, collapse can occur at fairlylow levels of stress, equivalent only to overburden soil pressure.Additionalloads, such as traffic loading or the presence of a bridge structure, add tothe collapse, especially of shallow collapsible soil.The triggering mechanismfor collapse, however, is the addition of water.Highway Problems Resulting from Collapsible SoilsNonuniform collapse can result from either a nonhomogeneous subgradedeposit in which differing degrees of collapse potential exist and/or fromnonuniform wetting of subgrade materials.When differential collapse ofsubgrade soils occurs, the result is a rough, wavy surface, and potentiallymany miles of extensively damaged highway.There have been several re-ported cases for which differential collapse has been cited as the cause ofroadway or highway bridge distress.A few of these in the Arizona and NewMexico region include sections of 1-10 near Benson, Arizona, and sectionsof 1-25 in the vicinity of Algadonas, New Mexico(Lovelace et al.1982;Russman 1987).In addition to the excessive waviness of the roadway sur-face, bridge foundations failures, such as the Steins Pass Highway bridge,1-10, in Arizona, have frequently been identified with collapse of foundationsoils.Identification of Collapsible SoilsThere have been many techniques proposed for identifying a collapsiblesoil problem.These methods range from qualitative index tests conducted on4disturbed samples, to response to wetting tests conducted on relatively un-disturbed samples, to in situ meausrement techniques.In all cases, the en-gineer must first know if the soils may become wetted to a water contentabove their natural moisture state, and if so, what the extent of the potentialwetted zone will be.Most methods for identifying collapsible soils are onlyqualitative in nature, providing no information on the magnitude of the col-lapse strain potential.These qualitative methods are based on various func-tions of dry density, moisture content, void ratio, specific gravity, and At-terberg limits.In situ measurement methods appear promising in some cases, in that manyresearchers feel that sample disturbance is greatly reduced, and that a morenearly quantitative measure of collapse potential is obtainable.However,in situ test methods for collapsible soils typically suffer from the deficien-cy of an unknown extent and degree of wetting during the field test.Thismakes a quantitative measurement difficult because the zone of materialbeing influenced is not well-known, and, therefore, the actual strains, in-duced by the addition of stress and water, are not well-known.In addition,the degree of saturation achieved in the field test is variable and usuallyunknown.Based on recently conducted research, it appears that the most reliablemethod for identifying a collapsible soil problem is to obtain the best qualityundisturbed sample possible and to subject this sample to a response to wet-ting test in the laboratory.The results of a simple oedometer test will indicatewhether the soil is collapsible and, at the same time, give a direct measureof the amount of collapse strain potential that may occur in the field.Potentialproblems associated with the direct sampling method include sample distur-bance and the possibility that the degree of saturation achieved in the fieldwill be less than that achieved in the laboratory test.The quality of an undisturbed sample is related most strongly to the arearatio of the tube that is used for sample collection.The area ratio is a measureof the ratio of the cross-sectional area of the sample collected to the cross-sectional area of the sample tube.A thin-walled tube sampler by definitionhas an area ratio of about 10-15%.Although undisturbed samples are bestobtained through the use of thin-walled tube samplers, it frequently occursthat these stiff, cemented collapsible soils, especially those containing gravel,cannot be sampled unless a tube with a much thicker wall is used.Samplershaving an area ratio as great as 56% are commonly used for Arizona col-lapsible soils.Further, it may take considerable hammering of the tube todrive the sample.The result is, of course, some degree of sample distur-bance, broken.bonds, densification, and a correspondingly reduced collapsemeasured upon laboratory testing.However, for collapsible soils, which arecompressive by definition, the insertion of the sample tube leads to localshear failure at the base of the cutting edge, and, therefore, there is lesssample disturbance than would be expected for soils that exhibit general shearfailure(i.e., saturated clays or dilative soils).Results of an ongoing studyof sample disturbance for collapsible soils indicate that block samples some-times exhibit somewhat higher collapse strains compared to thick-walled tubesamples.Block samples are usually assumed to be the very best obtainableundisturbed samples, although they are frequently difficult-to-impossible toobtain, especially at substantial depths.The overall effect of sample distur-bance is a slight underestimate of the collapse potential for the soil.675译文：湿陷性地基引起的路面问题作者：...摘要：在干旱环境中，湿陷性土壤组成的路基材料是很常见的，干旱环境中的气候条件、沉积以及风化作用都有利于湿陷性土的形成。
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矿产资源开发利用方案编写内容要求及审查大纲
矿产资源开发利用方案编写内容要求及《矿产资源开发利用方案》审查大纲一、概述
㈠矿区位置、隶属关系和企业性质。
如为改扩建矿山, 应说明矿山现状、
特点及存在的主要问题。
㈡编制依据
(1简述项目前期工作进展情况及与有关方面对项目的意向性协议情况。
(2 列出开发利用方案编制所依据的主要基础性资料的名称。
如经储量管理部门认定的矿区地质勘探报告、选矿试验报告、加工利用试验报告、工程地质初评资料、矿区水文资料和供水资料等。
对改、扩建矿山应有生产实际资料, 如矿山总平面现状图、矿床开拓系统图、采场现状图和主要采选设备清单等。
二、矿产品需求现状和预测
㈠该矿产在国内需求情况和市场供应情况
1、矿产品现状及加工利用趋向。
2、国内近、远期的需求量及主要销向预测。
㈡产品价格分析
1、国内矿产品价格现状。
2、矿产品价格稳定性及变化趋势。
三、矿产资源概况
㈠矿区总体概况
1、矿区总体规划情况。
2、矿区矿产资源概况。
3、该设计与矿区总体开发的关系。
㈡该设计项目的资源概况
1、矿床地质及构造特征。
2、矿床开采技术条件及水文地质条件。