水利水电工程专业外文翻译--边坡稳定性
土木专业外文翻译---简要的分析斜坡稳定性的方法
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICSInt. J. Numer. Anal. Meth. Geomech., 23, 439}449 (1999)SHORT COMMUNICATIONSANALYTICAL METHOD FOR ANALYSIS OF SLOPESTABILITYJINGGANG CAOs AND MUSHARRAF M. ZAMAN*t School of Civil Engineering and Environmental Science, University of Oklahoma,Norman, OK 73019, U.S.A.SUMMARYAn analytical method is presented for analysis of slope stability involving cohesive and non-cohesive soils.Earthquake effects are considered in an approximate manner in terms of seismic coe$cient-dependent forces. Two kinds of failure surfaces areconsidered in this study: a planar failure surface, and a circular failure surface. The proposed method can be viewed as an extension of the method of slices, but it provides a more accurate etreatment of the forces because they are represented in an integral form. The factor of safety is obtained by using the minimization technique rather than by a trial and error approach used commonly.The factors of safety obtained by the analytical method are found to be in good agreement with those determined by the local minimum factor-of-safety, Bishop's, and the method of slices. The proposed method is straightforward, easy to use, and lesstime-consuming in locating the most critical slip surface and calculating the minimum factor of safety for a given slope. Copyright ( 1999) John Wiley & Sons, Ltd.Key words: analytical method; slope stability; cohesive and non-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 many applications involving earth pressure was proposed by Coulomb in 1773. His solution approach for earth pressures against retaining walls 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 surfacesin 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 using circular 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 reasonable certainty 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 thesolution 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 morestraightforward 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 andgravels, the shear strength is directly proportional to the stress level:''tan f τσθ= （1）where f τ is the shear stress at failure, /σ the effective normal 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 isu 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 porepressure 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 more straightforward. Although it is possible, in principle, to use buoyant 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.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 normal and 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 average shear strength of the soil, and d τ the average shear stress developed along the potential failure surface.For cohesionless soils where c =0, the safety factor can be readily written from equation (7) as1tan tan tan s k F k αφα-=+ （8） It is obvious that the minimum value of F s occurs when a=b, and the failurebecomes 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 circularsurfaces. Figure 2 shows a potential circular sliding surface AB in two dimensions withcentre 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 the analytical solution of the slope stability problem addressed in this paper achievable and some of these assumptions would lead to restrictions in terms ofapplications (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 further numericalprocedure to permit specialcation of interslice shear forces Xl and Xr . Since Xl and Xr areinternal forces, ()l r X X -∑ must be zero for the whole section. Resolvingprerpendicularly and parallel to EF , one getssin cos T hdx k hdx γαγα=+ （9） cos csin N hdx k hdx γαγα=- （10）arcsin ,x a r 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 byy123tan ,,y x y h y b 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)cot ,L H l a β==+ （16）arcsin arcsin l a a r rϕ-=+ （17） 1323022()sin ()sin 1(cot )sec 23L ls L I y y dx y y dx H a b H rααββ=-+-⎡⎤=+-⎢⎥⎣⎦⎰⎰ （18）132302222222()cos ()cos tan tan 2()()623(tan )arcsin (tan )arcsin 221()arcsin()4()()26Ll s L I y y dx y y dxb r b 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 rααββββ=-+-⎡⎤=-+-+⎣⎦-⎛⎫⎛⎫+-+- ⎪ ⎪⎝⎭⎝⎭-⎡⎤--+-+--⎣⎦⎰⎰ （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 same procedure 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 ls 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，1230,tan ,,y y x y H y b β==== （24）0111cot ,cot ,22l a H l a H l a 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 thevalue of these variables where f takes on a minimum value, and then to calculate thecorresponding 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 anoptimization 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 (Figure4). 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 used instead 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 wasevaluated using two well-established methods of slope stability analysis. The local minimum factor-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-linearstress-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 analyticalmethod. 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).A number 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 conventionalmethod of slices, Liu obtained the minimum 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 can getmin 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 elementmethod-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) providing initial estimates for slope stability, and (c) conducting parametric sensitivity analyses forvarious 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. 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Chugh. &Variable factor of safety in slope stability analysis', Geotechnique, ¸ondon, 36(1), 57}64 (1986).23. B. M. Das. Principles of Soil Dynamics, PWS-Kent Publishing Company, Boston, 1993.24. S. L. Huang and K. Yamasaki. &Slope failure analysis using local minimum factor-of-safety approach', J. Geotech.Engng. ASCE, 119(12), 1974}1987 (1993).25. S. L. Kramer. Geotechnical Earthquake Engineering, Prentice Hall, Englewood Cli!s, NJ, 1996.26. D. Leshchinsky and C. Huang. &Generalized three dimensional slope stability analysis', J. Geotech. Engng. ASCE,118(11), 1748}1764 (1992).27. K. S. Li and W. White. &Rapid evaluation of the critical surface in slope stability problems', Int. J. Numer. Anal. Meth.Geomech., 11(5), 449}473 (1987).28. D. W. Taylor. Fundamentals of Soil Mechanics, Wiley, Toronto, 1948.29. U. S. Federal Highway Administration, Advanced ¹echnology for Soil Slope Stability, U.S. Dept. of Transportation,Washington, DC, 1994.30. Spencer (1969).31. Celestino and Duncan (1981).32. Spencer (1981).33. Chen (1970).34. Baker and Garber (1977).35. Bishop (1952).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。
水利水电工程英文专业词汇
水工建筑物专业词汇岸墙land wall坝顶dam crest，dam top坝踵dam heel坝趾dam toe板桩sheet pile边墩side pier，land pier变形模量deformation modulus鼻坎bucket lip毕肖普法Bishop method冰压力ice pressure剥离desquamation侧槽式溢洪道side channel Spillway沉降settlement齿墙cut-off trench冲沙闸（排沙闸）silt-releasing Sluice纯拱法independent arch method刺墙key-wall大头坝massive-head buttress dam*buttress 是扶壁的意思单宽流量discharge per unit width单曲拱坝single-curvature arch dam挡潮闸tidal sluice导流隧洞river diversion tunnel倒悬度Overhang degree底流消能energy dissipation by underflow地震作用earthquake action垫座cushion abutment动水压力hydrodynamic pressure断层fault堆石坝rock-fill dam多拱梁法multi-arch beam method阀门valve gate防浪墙wave wall防渗铺盖impervious blanket非常溢洪道emergency spillway分洪闸flood diversion sluice副坝auxiliary dam刚体极限平衡法limit equilibrium method for rigid block 拱坝arch dam拱冠梁crown cantilever拱冠粱法crown cantilever method工作桥service bridge固结灌浆consolidation grouting灌溉隧洞irrigation tunnel灌浆帷幕grout curtain管涌piping海漫apron extension横缝transverse joint虹吸式溢洪道siphon spillway蝴蝶阀butterfly valve护坡slope protection护坦apron弧形闸门radial gate滑雪道式溢洪道ski-jump spillway化学管涌chemical piping混凝土防渗墙concrete cut-off wall混凝土面板堆石坝concrete faced rock-fill dam 基本断面primary section简化毕肖普法simplified Bishop method浆砌石拱坝stone masonry arch dam浆砌石重力坝stone masonry gravity dam交通桥traffic bridge接触冲刷contact scouring接触灌浆contact grouting接缝灌浆joint grouting截水槽cut-off trench节制闸check sluice进水口water inlet进水闸inlet sluice井式溢洪道shaft spillway静水压力hydrostatic pressure均质坝homogeneous earth dam抗滑稳定分析analysis of stability against sliding 抗滑稳定性stability against sliding空腹重力坝hollow gravity dam空化cavitation空蚀cavitation erosion空注阀hollow jet valve宽缝重力坝slotted gravity dam宽尾墩flaring pier廊道gallery浪压力wave force理论计算theoretical computation拦河闸river sluice沥青混凝土asphalt concrete连拱坝multiple-arch dam流土soil flow流网法flow net method锚杆anchor rod面板face slab面流消能energy dissipation by surface flow模型试验model experiment泥沙压力silt pressure碾压混凝土坝Roller Compacted Concrete Dam 牛腿Corbel排沙隧洞silt-releasing tunnel排水drainage排水闸outlet sluice喷混凝土sprayed concrete平板坝flat slab buttress dam平面闸门plane gate破碎带crushed zone铺盖blanket砌石护坡stone pitching人工材料面板坝artificial material faced dam 人工材料心墙坝artificial material-core dam溶洞solution cavern软基重力坝gravity dam on soft foundation软弱夹层soft intercalated layer实用断面practical section试载法trial-load method双曲拱坝double-curvature arch dam水工建筑物hydraulic structure水工隧洞hydraulic tunnel，waterway tunnel 水力发电隧洞hydropower tunnel水利枢纽hydro-complex水力学方法hydraulics method水平施工缝horizontal joint水闸sluice弹性模量elastic modulus挑流消能energy dissipation by trajectory jet土工膜geomembrane土石坝earth-rock dam土质斜墙坝earth dam with inclined soil wall 土质斜心墙坝earth dam with inclined soil core 土质心墙坝earth dam with soil core帷幕灌浆curtain grouting温度荷载temperature load温度控制temperature control温度应力temperature stress温度作用temperature action无压隧洞free level tunnel消力池stilling pool消力戽roller bucket消能工energy dissipater泄洪隧洞spillway tunnel泄水建筑物discharge structure泄水孔outlet hole新奥法NATM（New Austrian Tunneling Method）胸墙breast wall扬压力uplift溢洪道spillway水垫塘plunge pool溢流坝overflow dam、翼墙wing wall应力分析stress analysis优化设计optimization design有限单元法finite element method有压隧洞pressure tunnel闸墩pier闸门gate闸门槽gate slot正槽式溢洪道normal channel spillway整体式重力坝monolithic gravity dam趾板toe slab支墩坝buttress dam重力坝gravity dam重力墩gravity abutment 周边缝peripheral joint 驻波standing wave锥形阀cone valve自由跌流free drop自重dead weight纵缝longitudinal joint键槽key strench伸缩缝contraction joint 施工缝construction joint 反弧段flip bucket拦污栅trash rack渐变段transition泄槽chute发电进水口power intake 通气管air vent检修门bulkhead gate事故门emergency gate 工作门service gate堰weir通气管air vent胸墙breast wall梁beam柱column回填混凝土backfill concrete 接地earth一期混凝土primary concrete 二期混凝土secondary concrete 叠梁门stoplog门机gantry crane止水waterstop钢筋reinforcement模板formwork围堰cofferdam马道bench；berm蜗壳volute水轮机turbine电站power house车间workshop发电机generator变电站transformer station副厂房auxiliary power house安装间erection bay尾水闸门tail lock尾水渠tailrace引水渠approach channel前池fore bay导墙lead wall隔墙partition wall接触灌浆contact grouting回填混凝土backfill concrete帷幕灌浆curtain grouting挡墙retaining wall港口harbour港口建筑物port structure船闸navigation lock船闸充水lock filling船闸充水和泄水系统locking filling and emptying system 船闸前池upper pool船闸上下游水位差lock lift船闸闸首lock head升船机ship elevator；ship lift鱼道fish canal旁通管by-pass 齿槽cut-off wall。
水利专业名词(中英文对照)
水利专业名词（中英）A安全储备safety reserve安全系数safety factor安全性safety岸边溢洪道river-bank spillway岸边绕渗by-pass seepage around bank slope岸墙abutment wall岸塔式进水口bank-tower intakeB坝的上游面坡度upstream slpoe of dam坝的下游面downstream face of dam坝顶dam crest坝顶长度crest length坝顶超高freeboard of dam crest坝高dam height坝顶高程crest elevation坝顶宽度crest width坝段monolith坝基处理foundation treatment坝基排水drain in dam foundation坝基渗漏leakage of dam foundation坝肩dam abutment坝壳dam shell坝坡dam slope坝坡排水drain on slope坝体混凝土分区grade zone of concrete in dam 坝体排水系统drainage system in dam坝型选择selection of dam type坝址选择selection of dam site坝趾dam toe坝踵dam heel坝轴线dam axis本构模型constitutive model鼻坎bucket比尺scale比降gradient闭门力closing force边墩side pier边界层boundary layer边墙side wall边缘应力boundary stress变形观测deformation observation变中心角变半径拱坝variable angle and radius arch dam 标准贯入试验击数number of standard penetration test 冰压力ice pressure薄壁堰sharp-crested weir薄拱坝thin-arch dam不均匀沉降裂缝differential settlement crack不平整度irregularityC材料力学法method of strength of materials材料性能分项系数partial factor for property of material 侧槽溢洪道side channel spillway侧轮side roller侧收缩系数coefficient of side contraction测缝计joint meter插入式连接insert type connection差动式鼻坎differential bucket掺气aeration掺气槽aeration slot掺气减蚀cavitation control by aeration厂房顶溢流spill over power house沉降settlement沉井基础sunk shaft foundation沉沙池sediment basin沉沙建筑物sedimentary structure沉沙条渠sedimentary channel沉陷缝settlement joint沉陷观测settlement observation衬砌的边值问题boundary value problem of lining 衬砌计算lining calculation衬砌自重dead-weight of lining承载能力bearing capacity承载能力极限状态limit state of bearing capacity 持住力holding force齿墙cut-off wall冲击波shock wave冲沙闸flush sluice冲刷坑scour hole重现期return period抽排措施pump drainage measure抽水蓄能电站厂房pump-storage power house出口段outlet section初步设计阶段preliminary design stage初参数解法preliminary parameter solution 初生空化数incipient cavitation number初应力法initial stress method船闸navigation lock垂直升船机vertical ship lift纯拱法independent arch method次要建筑物secondary structure刺墙key-wall粗粒土coarse-grained soil错缝staggered jointD大坝安全评价assessment of dam safety大坝安全监控monitor of dam safety大坝老化dam aging大头坝massive-head dam单层衬砌monolayer lining单级船闸lift lock单线船闸single line lock挡潮闸tide sluice挡水建筑物retaining structure导流洞diversion tunnel导墙guide wall倒虹吸管inverted siphon倒悬度overhang等半径拱坝constant radius arch dam等中心角变半径拱坝constant angle and variable radius arch dam 底流消能energy dissipation by hydraulic jump底缘bottom edge地基变形foundation deformation地基变形模量deformation modulus of foundation地基处理foundation treatment地下厂房underground power house地下厂房变压器洞transformer tunnel of underground power house 地下厂房出线洞bus-bar tunnel of underground power house地下厂房交通洞access tunnel of underground power house地下厂房通风洞ventilation tunnel of underground power house地下厂房尾水洞tailwater tunnel of underground power house地下轮廓线under outline of structure地下水groundwater地形条件topographical condition地形图比例尺scale of topographical map地应力ground stress地震earthquake地震烈度earthquake intensity地质条件geological condition垫层cushion垫座plinth吊耳lift eye调度dispatch跌坎drop-step跌流消能drop energy dissipation跌水drop迭代法iteration method叠梁stoplog丁坝spur dike定向爆破堆石坝directed blasting rockfill dam动强度dynamic strength动水压力hydrodynamic pressure洞内孔板消能energy dissipation by orifice plate in tunnel 洞内漩流消能energy dissipation with swirling flow in tunnel 洞身段tunnel body section洞室群cavern group洞轴线tunnel axis陡坡steep slope渡槽短管型进水口intake with pressure short pipe断层fault堆石坝rockfill dam对数螺旋线拱坝log spiral arch dam多级船闸multi-stage lock多线船闸multi-line lock多心圆拱坝multi-centered arch dam多用途隧洞multi-use tunnelE二道坝secondary damF发电洞power tunnel筏道logway反弧段bucket反滤层filter防冲槽erosion control trench防洪flood preventi，flood control防洪限制水位restricted stage for flood prevention防浪墙parapet防渗墙anti-seepage wall防渗体anti-seepage body放空底孔unwatering bottom outlet非常溢洪道emergency spillway非线性有限元non-linear finite element method非溢流重力坝nonoverflow gravity dam分岔fork分洪闸flood diversion sluice分项系数partial factor分项系数极限状态设计法limit state design method of partial factor 封拱arch closure封拱温度closure temperature浮筒式升船机ship lift with floats浮箱闸门floating camel gate浮运水闸floating sluice辅助消能工appurtenant energy dissipationG刚体极限平衡法rigid limit equilibrium method刚性支护rigid support钢筋混凝土衬砌reinforced concrete lining钢筋计reinforcement meter钢闸门steel gate高边坡high side slope高流速泄水隧洞discharge tunnel with high velocity工程管理project management工程规划project plan工程量quantity of work工程设计engineering design工程施工engineering construction工作桥service bridge工作闸门main gate拱坝坝肩岩体稳定stability of rock mass near abutment of arch dam 拱坝布置layout of arch dam拱坝上滑稳定分析up-sliding stability analysis of arch dam拱坝体形shape of arch dam拱端arch abutment拱冠arch crown拱冠梁法crown cantilever method拱冠梁剖面profile of crown cantilever拱内圈intrados拱外圈extrados固结consolidation固结灌浆consolidation grouting管涌piping灌溉irrigation规范code，specification过坝建筑物structures for passing dam 过滤层transition layer过渡区transition zone过木机log conveyer过木建筑物log pass structures过鱼建筑物fish-pass structuresH海漫flexible涵洞culvert河道冲刷river bed scour荷载load荷载组合load combination横缝transverse joint横拉闸门horizontal rolling /sliding gate 洪水标准flood standard虹吸溢洪道siphon spillway厚高比thickness to hight ratio弧形闸门radial gate护岸工程bank-protection works护坡slope protection护坦apron戽琉消能bucke-type energy dissipation滑坡land slip滑楔法sliding wedge method滑雪道式溢洪道skijump spillway环境评价environment assessment换土垫层cushion of replaced soil回填灌浆backfill grouting混凝土concrete混凝土衬砌concrete lining混凝土防渗墙concrete cutoff wall混凝土面板concrete face slab混凝土面板堆石坝concrete-faced rockfill dam 混凝土重力坝concrete gravity damJ基本荷载组合basic load combination基本剖面basic profile基面排水base level drainage激光准直发method of laser alignment极限平衡法limit equilibrium method极限状态limit state坚固系数soundness coefficient剪切模量shear modulus剪切应力shear stress检查inspection检修闸门bulkhead简单条分法simple slices method建筑材料construction material简化毕肖普法simplified Bishop’s method渐变段transition键槽key/key-way浆砌石重力坝cement-stone masonry gravity dam 交叉建筑物crossing structure交通桥access bridge校核洪水位water level of check floo校核流量check flood discharge接触冲刷contact washing接触流土soil flow on contact surface节制闸controlling sluice结构可靠度reliability of structure结构力学法structural mechanics method 结构系数structural coefficient截流环cutoff collar截水槽cutoff trench进口段inlet进口曲线inlet curve进水喇叭口inlet bellmouth进水闸inlet sluice浸润面saturated area浸润线saturated line经济评价economic assessment井式溢洪道shaft spillway静水压力hydrostatic pressure均质土坝homogeneous earth damK开敞式溢洪道open channel spillway开裂机理crack mechanism勘测exploration survey坎上水深water depth on sill抗冲刷性scour resistance抗冻性frost resistance抗滑稳定安全系数safety coefficient of stability against sliding 抗剪断公式shear-break strength formula抗剪强度shear strength抗裂性crack resistance抗磨abrasion-resistance抗侵蚀性erosion-resistance抗震分析analysis of earthquake resistance颗粒级配曲线grain size distribution curve可靠度指标reliability index可行性研究设计阶段design stage of feasibility study空腹重力坝hollow gravity dam空腹拱坝hollow arch dam空化cavitation空化数cavitation number空蚀cavitation damage空隙水压力pore water pressure控制堰control weir枯水期low water period库区reservoir area宽顶堰broad crested weir宽缝重力坝slotted gravity dam宽高比width to height ratio扩散段expanding section扩散角divergent angleL拦沙坎sediment control sill拦污栅trash rack廊道gallery浪压力wave pressure棱体排水prism drainage理论分析theory analysis力法方程canonical equation of force method连续式鼻坎plain bucket联合消能combined energy dissipation梁式渡槽beam-type flume量水建筑物water-measure structure裂缝crack临界水力坡降critical hydraulic gradient临时缝temporary joint临时性水工建筑物temporary hydraulic structure流量discharge流速flow velocity流态flow pattern流土soil flow流网flow net流向flow direction露顶式闸门emersed gateM马蹄形断面horseshoe section脉动压力fluctuating pressure锚杆支护anchor support门叶gate flap迷宫堰labyrinth weir面流消能energy dissipation of surface regime 模型试验model test摩擦公式friction factor formula摩擦系数coefficient of friction目标函数objective functionN内部应力internal stress内摩擦角internal friction angle内水压力internal water pressure挠度观测deflection observation泥沙压力silt pressure粘性土cohesive soil碾压混凝土重力坝roller compacted concrete gravity dam 凝聚力cohesion扭曲式鼻坎distorted type bucketP排沙底孔flush bottom outlet排沙漏斗flush funnel排沙隧洞flush tunnel排水drainage排水孔drain hole排水设施drainage facilities抛物线拱坝parabolic arch dam喷混凝土支护shotcrete support喷锚支护spray concrete and deadman strut漂木道log chute平板坝flat slab buttress dam平衡重式升船机vertical ship lift with counter weight平面闸门plain gate平压管equalizing pipe坡率slope ratio破碎带crush zone铺盖blanketQ启闭机hoist启门力lifting force砌石拱坝stone masonry arch dam潜坝submerged dam潜孔式闸门submerged gate倾斜仪clinometer曲线形沉沙池curved sedimentary basin渠首canal head渠道canal渠系建筑物canal system structure取水建筑物water intake structureR人工材料心墙坝earth-rock dam with manufactured central core 人字闸门mitre gate任意料区miscellaneous aggregate zone溶洞solution cavern柔度系数flexibility coefficient褥垫式排水horizontal blanket drainage 软弱夹层weak intercalationS三角网法triangulation method三角形单元三心圆拱坝三轴试验扇形闸门上游设计洪水位设计基准期设计阶段设计阶段划分设计流量设计状况系数设计准则伸缩缝渗流比降渗流变形渗流分析渗流量渗流体积力渗流系数生态环境生态平衡失效概率施工导流施工缝施工管理施工条件施工图阶段施工进度实体重力坝实用剖面实用堰事故闸门视准线法收缩段枢纽布置triangular element three center arch dam triaxial testsector gate upstreamdesign flood level design reference period design stagedividing of design stage design discharge design state coefficient design criteria contraction joint seepage gradient seepage deformation seepage analysis seepage discharge mass force of seepage permeability coefficient ecological environment ecological balance probability of failure construction diversion construction jointconstruction managementconstruction conditionconstruction drawing stageconstruction progresssolid gravity dampractical profilepractical weiremergency gatecollimation methodconstringent sectionlayout of hydraulic complex输水建筑物water conveyance structure竖式排水vertical drainage数值分析numerical analysis双层衬砌double-layer lining双曲拱坝double curvature arch dam水电站地下厂房underground power house 水电站建筑物hydroelectric station structure 水垫塘cushion basin水工建筑物hydraulic structure水工隧洞hydraulic tunnel水环境water environment水库吹程fetch水库浸没reservoir submersion水库渗漏reservoir leakage水库坍岸reservoir bank caving水库淹没reservoir inundation水力资源water power resource水力劈裂hydraulic fracture水利工程hydraulic engineering，water project 水利工程设计design of hydroproject水利工程枢纽分等rank of hydraulic complex 水利枢纽hydraulic complex水面线water level line水能hydraulic energy水平位移horizontal displacement水体污染water pollution水土流失water and soil loss水位急降instantaneous reservoir drawdown 水压力hydraulic pressu水闸sluice水质water quality水资源water resources顺坝longitudinal dike四边形单元quadrangular element塑性破坏failure by plastic flow塑性变形plastic deformation塑性区plastic range锁坝closure dike锁定器dog deviceTT型墩T-type pier塌落拱法roof collapse arch method塔式进水口tower intake台阶式溢流坝面step-type overflow face 弹塑性理论elastoplastic theory弹性基础梁beam on elastic foundation 弹性抗力elastic resistance弹性中心elastic centre弹性理论theory of elasticity特殊荷载组合special load combination 体形优化设计shape optimizing design 挑距jet trajectory distance挑流消能ski-jump energy dissipation挑射角exit angle of jet调压室surge tank贴坡排水surface drainage on dam slope通航建筑物navigation structure通气孔air hole土工复合材料geosynthetic土工膜geomembrane土工织物geotexile土石坝earth-rock dam土压力earth pressure土质材料斜墙坝earth-rock dam with inclined soil core 土质心墙坝earth-rock dam with central soil core驼峰堰hump weir椭圆曲线elliptical curveWWES型剖面堰WES curve profile weir外水压力external water pressure弯矩平衡moment equilibrium围岩surrounding rock围岩强度strength of surrounding rock围岩稳定分析围岩压力surrounding rock pressu帷幕灌浆curtain grouting维修maintenance尾水渠tailwater canal温度缝temperature joint温度计thermometer温度应变temperature strain温度应力temperature stress温降temperature drop温升temperature rise污水处理sewage treatment无坝取水undamed intake无粘性土cohesionless soil无压泄水孔free-flow outletX下游downstream现场检查field inspection橡胶坝rubber dam消力池stilling basin消能防冲设计design of energy dissipation and erosion control消能工energy dissipator校核洪水位water level of check flood 校核流量check flood discharge斜缝斜墙泄洪洞泄洪雾化泄水重力坝胸墙悬臂梁汛期Y压力计压缩曲线淹没系数扬压力养护液化溢洪道溢流面溢流前缘溢流重力坝翼墙翼墙式连接引航道引水渠引张线法应力分析应力集中应力应变观测应力重分布永久缝优化设计有坝取水有效库容预压加固预应力衬砌inclined joint inclined coreflood discharge tunnel flood discharge atomization overflow gravity damcantiever beamflood periopressure meter compressive curve coefficient of submergence upliftcureliquifactionspillwayoverflow facelength of overflow crest overflow crestoverflow gravity dam wing wallwing wall type connection approach channel diversion canaltense wire method stress analysisstress concentrationstress-strain observationstress redistributionpermanent jointoptimizing designbarrage intakeeffective storagesoil improvement by preloading prestressed lining原型prototype约束条件constraint condition允许水力坡降allowable hydraulic gradient Z增量法increment method闸底板floor of slui闸墩pier闸孔sluice opening闸孔跨距span of sluice opening闸门槽gate slot闸室chamber of sluice闸首lock head闸址sluice site正槽溢洪道chute spillw正常使用极限状态limit state of normal operation 正应力normal stress正常溢洪道main spillw支墩坝buttress dam止水watertight seal止水装置sealing device趾板toe slab趾墩toe pier滞回圈hysteresis loop主应力principal stress纵缝longitudinal joint阻尼比damped ratio作用action作用水头working pressure head最优含水率optimum moisture content。
边坡的稳定性英语作文
边坡的稳定性英语作文Civil engineering projects often involve the construction of structures on or near slopes, making the stability of these slopes a critical consideration. The stability of a slope is influenced by a variety of factors, including the geological composition of the soil, the angle of the slope, the presence of water, and the load applied to the slope. In this essay, we will explore the concept of slope stability and the methods used to ensure it.Firstly, it is essential to understand the geological factors that contribute to slope stability. Soil types range from cohesive clay to granular sand, each with different properties that affect stability. Cohesive soils tend to hold together better, providing greater resistance to sliding, whereas granular soils are more prone to erosion and canshift more easily.The angle of the slope is another critical factor. Steeper slopes are inherently less stable due to the increased gravitational force acting on them. Civil engineers must carefully calculate the optimal angle for a slope to balance the need for stability with the requirements of the project.Water is a common enemy of slope stability. It can infiltrate soil, increasing the weight on the slope and reducing thesoil's shear strength. Proper drainage systems must be designed and implemented to prevent water from compromisingthe stability of a slope.Loads applied to a slope, such as the weight of a building or the pressure from traffic, also play a significant role inits stability. Engineers must calculate these loads anddesign the slope to withstand them without failure.To ensure slope stability, engineers employ various methods. One common technique is the use of retaining walls, which physically hold the soil in place and prevent it from sliding. Another method is slope reinforcement, where steel rods or other materials are used to strengthen the soil and increaseits resistance to movement.Monitoring is also a crucial part of maintaining slope stability. Regular inspections and geological assessments can identify potential issues before they become critical. Modern technology, such as remote sensing and geotechnical instruments, can provide real-time data on the condition of a slope.In conclusion, the stability of slopes is a complex issuethat requires a multifaceted approach. By understanding the geological, hydrological, and mechanical factors at play,civil engineers can design and maintain slopes that are safe and stable for the structures built upon them. The use of modern engineering techniques and ongoing monitoring ensures that these critical civil engineering elements remain secure and functional for the lifetime of the project.。
水利水电工程专业英语段翻译
•Owingto the fact that electr icity can be transm itted from whereit is genera ted to whereit is needed by meansof powerlinesand transf ormer s, largepowerstatio ns can be builtin remote places far fromindust rialcenter s or largecities, as is citedthe case with hydroe lectr ic powerstatio ns that are insepa rable from watersource s.•由于电力可以从发电的地方通过电线和变压器输送到需要用电的地方，因此大型电站可以建在远离工业中心或大城市的地方，离不开水源的水力发电站就常常是这样建立的。
Ideall y suited to narrow canyon s compos ed of rock, the archdam provid es an econom icaland effici ent struct ure to contro lthe stream flow. The load-carryi ng capaci ty of an arch damenable s the design er to conser ve materi al and stillmainta in anextrem ely safe struct ure.•拱坝最适合于修建在岩石峡谷中，它是一种控制河道中水流经济而有效的建筑物。
一座拱坝的承载能力足以使设计人员用较少的材料而仍能建成极为安全的结构。
边坡稳定slopstability
b
▪ Assumptions (假定):
▪ no ground water table (没有地下水)
z
▪ homogeneous cohesionless soil (均质
无粘性土)
▪ failure surface is parallel to the
surface of the slope (滑动面与坡面
▪ For the slope stability analysis using the LEM, two
analyses are considered for each slope: ▪ Effective Stress Analysis (c´ and ´) that represents
drained or long-term behaviour of the slope (有效应 力分析对应边坡长期的稳定) ▪ Total Stress Analysis (cu) that represents undrained or short-term behaviour of the slope (总应力分析对应 边坡短期的稳定)
平行)
▪ The slope is inclined at angle to the
slope (滑动面为平面与坡面平行 )
Sliding mass (滑体)
Sliding surface or weak zone (滑动面
或软弱层)
Detached landslide deposit
(ii) Rotational slides ▪ Sliding surface is an arc which is common
▪ In general, the sliding surface is assumed to be a circular arc for clays or a logarithmic spiral for sands and gravels.
非线性破坏准则的边坡稳定性分析 毕业论文外文文献翻译
Slope Stability Analysis withNonlinear Failure CriterionIntroductionThe determination of the slope stability is a very important issue to geotechnical engineers. Many researchers have attempted to develop and elaborate the methods for slope stability evaluation. The proposed methods in the past for stability analysis may be classified into the following four categories: 1：the limit equilib-rium including the traditional slices method, 2：the characteristic line method, 3：The limit analysis method including upper andlower bound approaches, and 4：the finite element or finite difference numerical techniques. Among them, the slices method has almost dominated the geotechnical profession for estimating the stability of soil and rock slopes. This is due to the fact that the slices method is very simple, cumulated on the use of the method, and the method is the most known and widely accepted by practicing engineers.Until now, a linear MC failure criterion is commonly used in the limit analysis of stability problems. The reason is probably that a linear MC failure criterion can be expressed as circles. This characteristic makes it possible to approximate the circles by a failure surface, which is a linear function of the stresses in the stress space for plane strain problems. Thus, based on the upperand lower bound theorems, formulations of the stability or bearing capacity problems are linear programming problems.However, experiments have shown that the strength envelope of geomaterials has the nature of nonlinearity ~Hoek 1983; Agaret al. 1985; Santarelli 1987!. When applying an upper bound theorem to estimate the influences of a nonlinear failure criterion on bearing capacity or stability, the main problem, which many researchers have encountered, is how to calculate the rate of work done by external forces and the rate of energy dissipation alongvelocity discontinuities. Suitable methods for solving this problem can be mainly classified into two types. The first type of method is using a variational calculustechnique. Baker and Frydman ~1983! applied the variational calculus technique to derive the governing equations for the bearing capacity of a stripfooting resting on the top horizontal surface of a slope. Zhang and Chen ~1987!converted the complex differential equations obtained using the variational calculus technique into an initial value problem and presented an effective numerical procedure, called an inverse method, for solving a plane strain stability problem using a general nonlinear failure criterion. They gave numerical results of stability factors of a simple infinite homogenous slope without surcharge. The second type of method is using a ‘‘tangential’’ technique. Drescher and Christopoulos ~1988! and Collinset al. ~1988! proposed a simpler alternati ve ‘‘tangent’’ technique to evaluate the stability factors of an infinite and homogeneous slope without surcharge. They showed that upper bound limit analysis solutions could be obtained by means of a series of linear failure surfaces which are tangent to an exceed the actual nonlinear failure surface, together with utilizing the previously calculated linear stability factors, NL, given by Chen ~1975!.This paper develops an improved method using a ‘‘generalized tangential’’ technique. This method employs the tangential line ~a linear MC failure criterion!, instead of the actual nonlinear failure criterion, to formulate the work and energy dissipation.A ‘‘Generalized Tangential’’ TechniqueA limit load computed from a linear failure surface, which always circumscribes the actual nonlinear failure surface, will be an upper bound value on the actual limit load ~Chen 1975!. This is due to the fact that the strength of the circumscribing the actual nonlinear failure surface is equal to or larger than that of the actual failure surface. In the present analysis, a tangential line to a nonlinear failure criterion at point M is used and shown in Fig.It can be seen that the strength of the tangential line equals or exceeds that of a nonlinear failure criterion at the same normal stress. Thus, the linear failure criterion represented by the tangential line will give an upper bound on the actual load for the material, whose failure is governed by a nonlinear failure criterion.In fact, manyresearchers~Lymser 1970; Sloan 1989; Sloan andKleeman 1995; Yu et al. 1998; Kim et al. 1999, 2002! Have adopted this approach in their limit analyses.Upper Bound Solutions with a Nonlinear Failure CriterionIn an upper bound limit analysis, solutions depend on the choices of kinematically admissible velocity fields. To obtain better solutions ~lower upper bounds!, work has to be done for trial kinematically admissible velocity fields, as many as possible. Rotational failure mechanisms have been considered when using an upper bound approach ~Chen 1975!. In the stability analysis of a slope, comparing with different translational failure mechanisms,Chen ~1975! concluded that a rotational failure mechanism is the most efficient one and that the rotational failure mechanisms lead to lower critical heights or stability factors than those obtained by using other translational failure mechanisms. The kinematical admissibility condition in the upper bound theorem requires that therotational failure surface for a perfect-plastic body collapse must be a log-spiral surface ~log-spiral line for plane strain problems!.Basic ideas in Chen ~1975! on the rotational log-spiral surfacesare adopted in the method of the paper.ConclusionsAn improved method using a ‘‘generalized tangential’’ technique app roximating a nonlinear failure criterion is developed based on the upper bound theorem of plasticity and is used to analyze the stability of slopes in this paper. For a slope as shown in Fig. without surcharge, the values of the stability factor calculated using the proposed upper bound method are almost equal to those obtained by Zhang and Chen ~1987!For a translational failure mechanism of the vertical cut slope identical solutions are obtained using the present upper bound method and a lower bound method.非线性破坏准则的边坡稳定性分析介绍：边坡稳定对于土质工程来说是一个非常重要的问题。
水利水电工程专业外文翻译--边坡稳定性
外文翻译Stability of Slopes1.1 Introduction Gravitational and seepage forces tend to cause instability in natural slopes, in slopes of embankments and earth dams. The most important types of slope failure arc illustrated in Fig.1.1. In rotational slips the shape of the failure surface in section may be a circular are or a non-circular curve. In general, circular slips are associated with homogeneous soil conditions and non-circular slips with non- homogeneous conditions. Translational and compound slips occur where the form of failure surface is influenced by the presence of an adjacent stratum is at a relatively shallow depth bellow the surface of the slope: the failure surface tends to be plane and roughly parallel to the slope. Compound slips usually occur where the adjacent stratum is at greater depth, the failure surface consisting of curved and plane sections.Figure 1.1 Type of slope failureIn practice, limiting equilibrium methods are used in the analysis of slope stability. It is considered that failure is on the point of occurring along an assumed or a known failure surface. The shear strength required to maintain a condition of the limiting equilibrium is compared with the available shear strength of the soil, giving the average factor safety along the failure surface. The problem is considered in two dimensions, conditions of plane strain being assumed. It has been shown that two-dimensional analysis gives a conservative result for a failure on a three-dimensional (dish-shaped) surface.Figure 1. 2 The φu =0 analysis1.2 Analysis for the Case of φu =0The analysis, in term of total stress ,covers the case of a fully-saturated clay under undrained conditions, i.e. for the condition immediately after construction. Only moment equilibrium is considered in the analysis. In section, the potential failure surface is assumed to be a circle arc. A trial failure surface (centre O, radius and length L a ) is shown in Fig 1.2.Potential instability is due to the total weight of the soil mass(W per unit length) above the failure surface. For equilibrium the shear strength which must be mobilized along the failure surface is expressed as: τm =f F τ=Cu Fwhere F is the factor of safety with respect to shear strength. Equation momentabout O:Wd=Cu FL a r F=u a C L r Wd (1.1) The moments of any additional forces must be taken into account. In the event of a tension crack developing, as shown in Fig1.2,the arc length L a is shortened and a hydrostatic force will act normal to the crack if the crack fills with water. It is necessary to analyze the slope for a number of trial failure surfaces in order that the minimum factor of safety can be determined.Example 1.1A 45°slope is excavated to a depth of 8m in a deep layer of unit weight 19kN/m 3: the relevant shear strength parameters are c u =65kN/m 3 and φu =0.Determine the factor of safety for the trial surface specified in Fig1.3.In Fig1.3, the cross-sectional area ABCD is 70m 2.The weight of the soil mass=70×19=1330m 2.The cent roid of ABCD is 4.5m from O.The angle AOC is 89.5°and radius OC is 12.1m.The arc length ABC is calculated as 18.9m.The factor of safety is given by:F=u a C L r Wd=6518.912.11330 4.5⨯⨯⨯6518.912.11330 4.5⨯⨯⨯ =2.48This is the factor of safety for the trial failure surface selected and is not necessarily the minimum factor of safety.Figure 1.3 example 1.11.3 The φ-Circle MethodThe analysis is in terms of total stress. A trial failure surface , a circular arc (centre o, radius r) is selected as shown in Fig 1.4.If the shear strength parameters are c u and φu ,the shear strength which must be mobilized for equilibrium is:τm =f Fτ=l ∑ =c m +tan m σφ Figure 1.4 The φ-circle methodWhere F is the factor of safety with respect to shear strength .For convenience the following notation is introduced:c m =u cc F (1.2) tan m φ=tan u F φφ (1.3) it being a requirement that:F C =F φ=FAn element ab, of length l, of the failure surface is considered, the element being short enough to be approximated to a straight line. The forces acting on ab (per unit dimension normal to the section) are as follows:(1) the total normal force 1σ;(2) the component of shearing resistance c m l;(3) the component of shearing resistance 1σtan m φ.If each force c m l along the failure surface is split into components perpendicular and parallel to the chord AB, the perpendicular components sum to zero and the sum of the parallel components is given by:C=c m L c (1.4) where L c is the chord length AB. The force C is thus the resultant, acting parallel to the chord c m l. The line of application of the resultant force C can be determined by taking moments about the centre O, then:C r c =r m c l ∑i.e.c m L c r c =rc m L awhere La=l ∑ is the arc length AB.Thus,r c =a CL L r (1.5) The resultant of the forces 1σ and 1σtan m φ on the element ab acts at angle m φ to the normal and is the force tangential to a circle, centre O, of radius r sin m φ: this circle is referred to as the φ-circle. The same technique was used in Chapter 5.The overallresult (R) for the arc AB is assumed to be tangential to the φ-circle. Strictly, the resultant R is tangential to a circle of radius slightly greater than r sin m φ but the error involved in the above assumption is generally insignificant.The soil mass above the trial failure surface is in equilibrium under its totalweight (W) and the shear resultants C and R. The force W is known in magnitude and direction; the direction only of the resultant C is known. Initially a trial value of F φ is selected and the corresponding value of m φ is calculated from equation1.3.For equilibrium the line of application of the resultant R must be tangential to the φ-circle and pass though the point of intersection of the forces W and C. The force diagram can then be drawn, from which the value of C can be obtained .Then:c m =CC L andF C =Cu Cm It is necessary to repeat the analysis at least three times, starting with different values of F φ.If the calculated values of F C are plotted against the corresponding values of F φ,the factor of safety corresponding to the requirement F C =F φ can be determined .The whole procedure must be repeated for a series of trial failure surfaces in order that the minimum factor of safety is obtained.For an effective stress analysis the total weight W is combined with the resultant boundary water force on the failure mass and the effective stress parameters c ′and φ′used.Based on the principle of geometric similarity, Taylo r （1.13）published stability coefficients for the analysis of homogeneous slopes in terms of total stress. For a slope of height H the stability coefficients for the analysis of homogeneous slopes in terms of total stress. For a slope of height H the stability coefficient (N s ) for the failure surface along which the factor of safety is a minimum is:N s =u C F Hγ (1.6) Values of N s , which is a function of the slope angle β and the shear strength parameter u φ,can be obtained from Fig 1.5.For u φ=0,the value of N s also depends on the depth factor D, where DH is the depth to a firm stratum.Firm stratumFigure 1.5 Taylo r ′s coefficients.In example 1.1, β=45°, u φ=0,and assuming D is large, the value of N s is 0.18.Then from equation 1.6:F=s Cu N H γ = 650.18198⨯⨯ =2.37Gibson and Morgenste r n 〔1.4〕published stability coefficients for slopes in normally-consolidated clays in which the untrained strength c u (u φ=0) varies linearly with depth.Figure 1.6 Example 1.2Example 1.2An embankment slope is detailed in Figure 1.6.Fir the given failure surface. Determine the factor of safety in terms of total stress using the φ-circle method. The appropriate shear strength parameters are c u =15kN/m 2 and u φ=15°: the unit weight of soil is 20 kN/m 2.The area ABCD is 68 m 2 and the centroid (G) is 0.60m from the vertical through D. The radius of the failure arc is 11.10m.The arc length AC is 19.15 m and the chord length AC is 16.85m.The weight of the soil mass is:W=68×20=1360 k N/mThe position of the resultant C is given by:r c =a CL L r = 19.1516.85×11.10 Now:m φ=tan -1(tan15F φ) Trial value of F φ are chosen, the corresponding values of r sin m φ are calculated and the φ-circle drawn shown in Fig.1.6.The resultant C(for any value of F φ) acts in a directions parallel to the chord AC and at distance r c from O. The resultant C(for any value F φ) acts in a direction parallel to the chord AC and at distance r c from O. The forces C and W intersect at point E. The resultant R, corresponding to each value of F φ, passes through E is tangential to the appropriate φ-circle. The force diagrams are drawn and the values of C determined.The results are tabulated below.If F c is plotted against F φ(Fig.1.6) it is apparent that:F=F C =F φ=1.431.4 The Method of SlicesIn this method the potential failure surface, in section, is against assumed to be a circle arc with centre O radius r. The soil mass (ABCD) above a trial failure surface(AC) is divided by vertical planes into series of slices of width b, as shown in Fig.1.7. The base of each slice is assumed to be a straight line. For any slice the inclination of the base to the horizontal is α and the height, measured on the centerline, is h. The factor of safety is defined as the ratio of the available shear strength (f τ) to the shear strength (m τ) which must be mobilized to maintain a condition of limiting equilibrium. i.e.F=f mττ The factor of safety is taken to be the same for each slice, implying that there must be mutual support between the slice. i.e. forces must act between the slices.The forces (per unit dimension normal to the section) acting on a slice are listed below.(1) The total weight of slice, W=γbh (γsat where appropriate)(2) The total normal force on the base, N. In general this force has two components.The effective normal force N′ (equal to σ′l ) and the boundary water force ul, where u is the pore water pressure at the center of the base and l is the length of the base.(3) The shear force on the sides, T=m τl.(4) The total normal forces on the sides,E 1 and E 2.(5) The shear forces on the sides, X 1 and X 2.Any external forces must also be included in the analysis.The problem is statically indeterminate and in order to obtain a solution assumptions must be made regarding the inter-slice forces E and X: the resulting solution for factor of safety is not exact.Considering moments about O, the sum of the moments of the shear forces T on the failure arc AC must equal the moment of the weight of the soil mass ABCD. For any slice the lever arm of w is r sin α, therefore:Tr ∑=sin rW α∑Figure 1.7 The method of slices.Now,T=m τl=f l F τ ∵ f l F τ∑=sin W α∑∴ F=sin fl W τα∑∑ For an analysis in terms of effective stress:F=(tan )sin c l W σφα'''+∑∑ or, F= tan sin c La N W φα'''+∑∑ （1.7） where L a is the arc length AC. Equation 1.7 is exact but approximations are introduced in determining the forces N′. For a given failure arc the value of F will depend on the way in which the forces N′ are estimated.The Fellenius SolutionIn the solution it is assumed that for each slice the resultant of the inter-slice forces is zero. The solution involves resolving the forces on each slice normal to the base, i.e.:cos N W ul α'=-Hence the factor of safety in terms of effective stress ( equation 1.7 ) is given by: F=tan (cos )sin c La W ul W φαα''+-∑∑ (1.8)The components cos W α and sin W α can be determined graphically for each slice. Alternatively, the value of α can be measured or calculated. Again, a series of trial failure surfaces must be chosen in order to obtain the minimum factor of safety. This solution underestimates the factor of safety :the error, compared with more accurate methods of analysis, is usually within the range of 5-20﹪.For an analysis in terms of total stress the parameters c u and φu are used and the value of u in equation 1.8 is zero. If φu =0 the factor of safety is given by:F=sin u a c L W α∑(1.9)As N ′does not appear in equation 1.9 an exact value of F is obtained.The Bishop Simplified SolutionIn this solution it is assumed that the resultant forces on the sides of the slices are horizontal, i.e.X 1-X 2=0For equilibrium the shear force on the base of any slice is:T= 1(tan )c l N Fφ'''+ Resolving forces in the vertical direction:cos cos sin tan sin c l N W N ul F Fαααφα''''=+++ ∴ tan sin (sin cos )/(cos )c l N W ul F F φαααα'''=--+ (1.10) It is convenient to substitute:l= sec b αFrom equation 1.7, after some rearrangement:1sec [{()tan }]tan tan sin 1F c b W ub W Fαφαφα''=+-'+∑∑ (1.11) The pore water press can be related to the tota l ‘fill pressure ’ at any point by means of the dimensionless pore press ratio , defined as:u u r hγ= (1.12) (sat γ where appropriate )For any slice,/u u r W b =Hence equation 1.11 can be written: 1sec [{(1)tan }]tan tan sin 1u F c b W r W Fαφαφα''=+-'+∑∑ (1.13) As the factor of safety occurs on both sides of equation 1.13 a process of successive approximation must be used to obtain a solution but convergence is rapid. The method is very suitable for solution on the computer. In the computer program the slope geometry can be made more come complex, with soil strata having different properties and pore pressure conditions being introduced.In most problems the value of the pore pressure ratio u r is not constant overthe whole failure surface but, unless there are isolates regions of high pore pressure, an average value (weighted on an area basis) is normally used in design. Again, the factor of safety determined by this method is an underestimate but the error is unlikely to exceed 7﹪ and in most cases is less than 2﹪.Spencer [1.12] proposed a method of analysis in which the resultant inter-slice forces are parallel and in which both force and moment equilibrium are satisfied.Spencer showed that the accuracy of the Bishop simplified method, in which only moment equilibrium is satisfied, is due to the insensitivity of the moment equation to the slope of the inter-slice forces.Dimensionless stability coefficients for homogeneous slopes, based on equation 1.13, have been published by Bishop and Morgenstern[1.3]. It can be shown that for a given slope angle and given soil properties the factor of safety varies linearly with u r and can thus be expressed as:u F m nr =- (1.14)where m and n are the stability coefficients m and n are functions of β,φ', the dimensionless number /c h γ' and the depth factor D.Example 1.3Using the Fellenius method of slices, determined the factor of safety in terms of effective stress of the slope shown in Fig.1.8 for the given failure surface. The distribution of pore water pressure along the failure surface is given in the figure. The unit weight of the soil is 20 kN/m 3 and the relevant shear strength parameters are c '=10kN/m 2 and φ'=29°.The factor of safety is given by equation 9.8. The soil mass is divided into slices 1.5m wide. The weight(W) of each slice is given by:20 1.530/W bh h hkN m γ==⨯⨯=The height h for each slice is set off bellow the centre of the base and the normal and tangential components cos h α and sin h α respectively are determined graphically, as shown in Fig.1.8.Then:cos 30cos W h αα=andsin 30sin W h αα=Figure 1.8 Example 1.3.The arc length (L a ) is calculated as 14.35m. The results are tabulated below:cos 3017.50525/W kN m α=⨯=∑sin 308.45254/W kN m α=⨯=∑(cos )525132.8392.2/W ul kN m α-=-=∑tan (cos )sin ac L W ul F W φαα''+-=∑∑ (1014.35)(0.554393.2)254⨯+⨯= 1.5 Analysis of a Plane Translational SlipIt is assumed that potential failure surface is parallel to the surface of the slope and is at a depth that is small compared with the length of the slope. The slope can then be considered as being of infinite length, with end effects being ignored. The slope is inclined at angle β to the horizontal and the depth of the failure plane z, as shown in section in Fig.1.9. The water table is taken to be parallel to the slope at a height of mz(0＜m ＜1)above the failure plane. Steady seepage is assumed to be taking place in a direction parallel to the slope. The forces on the sides of any vertical slice are equal and opposite and the stress conditions are the same at every point on the failure plane.Figure 1.9 Plane translational slip.In terms of effective stress, the shear strength of the soil along the failure plane is:()tan f c u τσφ''=+-and the factor of safety is:f F ττ= The expressions for σ, τ and u are as follows:2{(1)}cos sat m m z σγγβ=-+{(1)}sin cos sat m m z τγγββ=-+2cos w u mz γβ=The following special cases are of interest. If c '=0 and m=0(i.e. the soil between the surface and the surface plane is not fully saturated), then:tan tan F φβ'= （1.15） If c '=0 and m=1(i.e. the water table conditions with the surface of the slope),then: sat tan tan F γφγβ''==If should be noted that when c '=0 the factor of safety is independent of the depth z. If c ' is greater to zero, the factor of safety is a function of z, and β may exceed φ' provided z is less than a critical value.For a total stress analysis the shear strength parameters u c and u φ are used and the value of u is zero.A long natural slope in fissured overconsolidated clay is inclined at 12° to the horizontal. The water table is at the surface and seepage is roughly parallel to the slope. A slip has developed on a plane parallel to the surface at a depth of 5m.The saturated unit weight of the clay is 20 kN/m 3. The peak strength parameters arec '=10kN/m 2 and φ'=26°; the residual strength parameters are r c '=0 and r φ'=18°. Determine the factor of safety along the slip plane(a) in terms of the peak strength parameters, (b) in terms of the residual strength parameters.With the water table at the surface (m=1), at any point on the slip plane:2cos sat z σγβ=22205cos 1295.5/kN m =⨯⨯=sin cos sat z τγββ=2205sin12cos1220.3/kN m =⨯⨯⨯=2cos w u z γβ=229.85cos 1246.8/kN m =⨯⨯=Using the peak strength parameters:()tan f c u τσφ''=+-210(48.7tan 26)33.8/kN m =+⨯=Then the factor of safety is given by:33.8 1.6620.3f F ττ=== Using the residual strength parameters, the factor of safety can be obtained from equation 1.16:tan tan r sat F γφγβ''=10.2tan180.7820tan12=⨯= 1.6 General Methods of AnalysisMorgenstern and Price[1.8] developed a general analysis in which all boundary and equilibrium conditions are satisfied and in which the failure surfacemay be any shape, circle ,non-circle and compound. The soil mass above the failure plane is divided into sections by a number of vertical planes and the problem is rendered statically determinate by assuming a relationship between the forces E and X on the vertical boundaries between each section. This assumption is of the form:()X f x E λ= (1.17)where f(x) is an arbitrary function describing the pattern in which the ratio X/E varies across the soil mass and λ is obtained as part of the solution along with the factor of safety F. The values of the forces E and X and the point of application of E can be determined at each vertical boundary. For any assuming function f(x) it is necessary to examine the solution in detail to ensure that it is physically reasonable (i.e. no shear failure or tension must be implied within the soil mass above the failure surface). The choice of the function f(x) does not appear to influence the computed value of F by more than about 5﹪ and f(x)=1 is a common assumption.The analysis involves a complex process of iteration for the value of λand F, described by Morgenstern and Price [1.9], and the use of a computer is essential.Bell [1.15] proposed a method of analysis in which all the conditions of equilibrium are satisfied and the assumed failure surface may be of any shape. The soil mass is divided into a number of vertical slices and statical determinacy is obtained by means of an assumed distribution of normal stress along the failure surface. Thus the soil mass is considered as a free body as is the case in the φ-circle method.Sarma [1.16] developed a method, based on the method of slices, in which the critical earthquale accelaration required to produce a condition of limiting equilibrium is determined. An assumed distribution of vertical inter-slice forces is used in the analysis. Again, all the conditions of equilibrium are satisfied and the assumed failure surface may be of any shape. The static factor of safety is the factor by which the shear strength of the soil must be reduced such that the critical acceleration if zero.The use of a computer is also essential for the Bell and Sarma methods and all solutions must be checked to ensure that they are physically acceptable.1.7 End-of-Construction and Long-Term StabilityWhen a slope is formed either by excavation or by the construction of an embankment the changes in total stress result in changes in pore water pressure in the vicinity of the slope and, in particular, along a potential failure surface. Prior toconstruction the initial pore water pressure(u 0) at any point is governed either by a static water table level or by a flow net for conditions of steady seepage. The change in pore water pressure at any point is is given theoretically by equation 4.17 or 4.18. The final pore water pressure, after dissipation of the excess pore water pressure, is governed by the static water table level or the steady seepage flow net for the final conditions after construction.If the permeability of the soil is low, a considerable time will elapse before any significant dissipation of excess pore water pressure will have taken place. At the end of construction the soil will be virtually in the undrained condition and a total stress analysis will be relevant. In principle an effective stress analysis is also possible for the end of construction condition using the pore water pressure (u) for this condition, where :o u u u =+∆However, because of its greater simplicity, a total stress analysis is generally used. It should be realised that the same factor of safety will not generally be obtained from a total stress and an effective stress analysis of the end-of-construction condition. In a total stress and an effective stress analysis of the end-of-construction condition. In a total stress analysis it is implied that the pore water pressures are those for a failure condition: in an effective stress analysis the pore water pressures used are those predicted for a non-failure condition. In the long-term, the fully-drained condition will be reached and only an effective stress analysis will be appropriate.If, on the other hand, the permeability of the soil is high, dissipation of excess pore water pressure will be largely complete by the end of construction. An effective stress analysis is relevant for all conditions with values of pore water pressure being obtained from the static water table level or the appropriate flow net.Pore water pressure may thus be an independent variable, determined from the static water table level or from the flow net for conditions of steady seepage, or may be dependent on the total stress changes tending to cause failure.It is important to identify the most dangerous condition in any practical problem in order that the appropriate shear strength parameters are used in design. Excavated and Natural Slopes in Saturated ClaysEquation 4.17, with B=1 for a fully-saturated clay, can be rearranged as follows:131311()()()22u A σσσσ∆=∆+∆+-∆-∆ (1.18) For a typical point P on a potential failure surface(Fig.9.10) the first term in equation 1.18 is negative and the second term will also be negative if the value ofA is less than 0.5. Overall, the pore water pressure change u ∆ is negative. The effect of the rotation of principal stress directions is neglected. As dissipation proceeds the pore pressure increases to the final value as shown in Fig.1.10. The factor of safety will therefore have a lower value in the long-term, when dissipation is complete, than at the end of construction.Figure 1.10 Pore press pressure dissipation and factor of safety (After Bishop and [1.2])Residual shear strength is relevant to the long-term stability of slopes in over consolidated fissured clays. A number of cases are on record in which failures in this type of clay have occurred long after dissipation of excess pore water pressure hade been completed. Analysis of these failures showed that the average shear strength at failure was bellow the peak value. In clays of this type it is suspected that large strains can occur locally due to the presence of fissures, resulting in the peak strength being reached, followed by a gradual decrease towards the residual value. The development of large local strains can lead eventually to a progressive slope failure. Fissures may not be the only cause of progressive failures: there is considerable nonuniformity of shear stress along a potential failure surface and local overstressing may initiate progressive failure. It should be realised, however, that the residual strength is reached only after a considerable slip movement has taken place and the strength relevant to first-time ′ slips lies between the peak and residual values. Analysis of failures in natural slopes in overconsolidated fissured clays has indicated that the residual shear strength is ultimately attained, probably as a result of successive slipping.1.8 Stability of Earth DamsIn the design of earth dams the factor of safety of both slopes must be determined as possible for the most critical conditions. For economic reasons an unduly conservative design must be avoided. In the case of the upstream slope the most critical stages are at the end of construction and during rapid drawdown of the reservoir level. The critical stages for the downstream slope are at the end of construction and during steady seepage when the reservior is full. The pore water pressure distribution at any stage has a dominant influence on the factor of safetyand in large earth dams it is common practice to install a piezometer system so that the actual pore water pressures can be measured at any stage and compared with the predicted values used in design(provided an effective stress analysis has been used) . Remedial action can then be taken if the factor of safety , based on the measured values, is considered too bellow.(a) End of ConstructionThe construction Period of an earth dam is likely to be long enough to allow partial dissipation of excess pore water pressure before the end of construction, especially in a dam with internal drainage. A total stress analysis, therefore, would result in too conservative a design. An effective stress analysis is preferable, using predicted values of r u .The pore pressure (u) at any point can be written as:0u u u =+∆where 0u is the initial value and u ∆ is the change in pore water pressure undrained conditions. In terms of the change in total major principal stress:01u u B σ=+∆Then:01u u r B h hσγγ∆=+ If it is assumed that the increase in total major principal stress is approximately equal to the fill pressure along a potential failure surface, then:0u u r B hγ=+ (1.19) The soil is partially saturated when compacted, therefore the initial pore water pressure (u 0) is negative. The actual value of u 0 depends on the placement water content, the higher the water content, the closer the value of u 0 to zero. The value of B also depends on the placement water content, the higher the water content, the higher the value of B . Thus for an upper bound:u r B = (1.20) The value of B must correspond to the stress conditions in the dam. Equations1.19 and 1.20 assume no dissipation during construction. A factor of safety as low as 1.3 may be acceptable at the end of construction provided there is reasonable confidence in the design data.If high values of u r are anticipated, dissipation of excess pore water pressure。
Chapter 7 Slope Stability Part 1 [边坡稳定
Chapter 7 Slope Stability Part 1 [边坡稳定]7.1 Types of slope failure [滑坡的类型]The most common types of slope failure [滑坡] are illustrated in Fig.7.1. Translational slide tends to occur where an adjacent weak zone [软弱层] of soil is at a relatively shallow depth below the surface of the slope. The failure surface tends to be plane and roughly parallel to the slope. [滑动面为平面与坡面平行]Rotational slide is common for cohesive soil [粘性土] (e.g. clays) slope. The shape of the failure surface in section may be a circular arc or a non-circular curve. In general circular slides are associated with homogeneous soil conditions and non-circular slides are associated with non-homogeneous soil conditions. [滑动面为一曲面]7.2 Methods of slope stability analysis [边坡稳定分析方法]The stability of a slope can be analysed using one or more of the following methods:– Limit equilibrium method (equilibrium of forces) [极限平衡法]– Limit analysis based on plasticity (equilibrium of stresses) [极限应力分析法]– Finite difference method [有限差分法]– Finite element method [有限元法]Although a finite element or a finite difference method is more flexible and general, in practice, the limit equilibrium method(LEM)is used in the slope stability analysis.In LEM, the soil is considered to be on the verge of failure along an assumed or a known sliding surface. [在某一假设滑动面,整个块体处于极限平衡状态] In general, the sliding surface is assumed to be a circular arc for clays or a logarithmic spiral for sands and gravels. The shear strength required to maintain a condition of limiting equilibrium is compared with the available shear strength of the soil, giving the average factor of safety along the sliding surface [安全糸数定义为抗剪力与下滑力之比]. The problem is normally considered in two dimensions. [土坡的稳定分析可简化为平面问题] For the slope stability analysis using the LEM, two analyses are considered for each slope:–Effective Stress Analysis [有效应力分析] (ESA) which represents drained or long-term behaviour of the slope. Cohesion (c’) and angle of internal friction (φ’) are used in the analysis.–Total Stress Analysis [总应力分析] (TSA) which represents undrained or short-term behaviour of the slope. Undrained shear strength (c u) is used in the analysis.7.3 Analysis of a plane translational slideIt is assumed that the potential failure surface is parallel to the surface of the slope and is at a depth that is small compared with the length of the slope. The slope can then be considered as being of infinite length, with end effects being ignored. [假设滑动面与坡面平行, 滑动块体深度远小于边坡长度, 边坡为无限长]The slope is inclined at angle α to the horizontal and the depth of the failure plane is z, as shown in Fig.7.2. Consider a slice of soil element of width b. [坡角为α, 滑动面深度z, 土条宽度为b] Assume the side forces on the soil element can be neglected in the stability analysis, ground water table is below the failure plane and the soil is cohesionless. [假设不考虑土条两边的合力,地下水位低于滑动面,无粘性土] The forces acting on the element are shown in Fig.7.2. W is weight of soil element [土条重量], T is shear force on the failure plane [平行于滑动面的下滑剪切力] and N is normal force on the failure plane [滑动面法线方向的分力]. Consider equilibrium of forces parallel to the slope surface, [边坡平行方向的静力平衡] α⋅=sin W T(7.1) Consider equilibrium of forces normal to the slope surface, [边坡法线方向的静力平衡] α⋅=cos W N(7.2) The available shear strength (T f ) along the failure surface is [滑动面上的抗剪力] φ⋅α⋅=φ⋅=tan cos W tan N T f(7.3)where φ is the angle of internal friction. Factor of safety (F S ) is defined as the ratio of T f and T. [安全糸数定义为抗剪力与下滑力之比]αφ=α⋅φ⋅α⋅==tan tan sin W tan cos W T T F f s (7.4)If water table coincides with the slope surface, the forces acting on the element are shown inFig.7.3. [地下水位于坡面] An additional hydrostatic force (U) is acting on the failure plane normal to the slope surface [边坡法线方向的静水力]. The equilibrium of forces parallel to the slope surface is also represented by equation (7.1). Consider equilibrium of forces normal to the slope surface,U 'N cos W +=α⋅ (7.5) The available shear strength (T f ) along the slip surface is φ⋅-α⋅=φ⋅=tan )U cos W (tan 'N T f(7.6)Then, factor of safety (F S ) is expressed as:α⋅φ⋅-α⋅==sin W tan )U cos W (T T F f s (7.7)The weight W is expressed as: sat b z W γ⋅⋅=(7.8)where γsat is saturated unit weight of soil. The hydrostatic force U is expressed asα⋅γ⋅⋅=α⋅γ⋅α⋅=α⋅=cos b z cos bcos z cos b u U w w 2 (7.9)where u is pore-water pressure at failure plane and γw is unit weight of water. Substitute equations (7.8) and (7.9) into equation (7.7) ()α⋅γφ⋅γ=α⋅γ⋅⋅φ⋅α⋅γ⋅⋅-α⋅γ⋅⋅⋅=α⋅φ⋅-α⋅==tan tan 'sin b z tan cos b z cos b z sin W tan )U cos W (T T F s s w s f s(7.10)Comparing Equations (7.4) and (7.10), the factor of safety is reduced by a factor γ’/γs if the water tablerises to the slope surface.7.4 Total stress analysis (φu = 0) [总应力分析]This total stress analysis covers the case of a fully saturated clay under undrained condition, or for the condition immediately after construction. [总应力分析合适用于饱和粘土在不排水条件下或短期的稳定分析] Only moment equilibrium is considered in the analysis. [满足力矩平衡条件] In section, the potential failure surface is assumed to be a circular arc [滑动面为弧形]. A trial failure surface (center O, radius r and length L [圆心为O,半径为r,弧长为L]) is shown in Fig.7.4. The failure of slope is mainly due self-weight (W) of the soil. Consider the moment at point O, the disturbing moment of W is expressed asd W M d ⋅=(7.11)where d is the moment arm of W from point O [d 是W 对滑弧圆心的力臂]. The forces resisting the rotation of the sliding soil mass are the shear forces (T f ) mobilised along the circular sliding surface. The resisting moment of T f at point O is expressed as r L c r T M u f r ⋅⋅=⋅=(7.12)where c u is undrained shear strength of the soil, L is length of the circular arc and r is radius of thecircular arc. Then factor of safety (F s ) is given bydW r L c M MF u d r s ⋅⋅⋅==(7.13)It is necessary to analyse the slope for a number of trial failure surfaces in order that the minimum factor of safety can be determined. If tension crack exists at the crest of the slope, the arc length L will be shortened. [当裂缝在坡顶出现,滑弧长度便会减小] The depth of the tension crack can be evaluated from the method presented in 土力学 p.196. [计算裂缝深度可参考土力学 p.196] If the crack is filled with water, a hydrostatic force will act normal to the crack. The additional moment of this hydrostatic force must be added to equation (7.11) for calculating the factor of safety of the slope. [当裂缝积水,计算安全糸数时公式(7.11)中必需考虑静水压力对滑弧圆心O 的力矩]Fig.7.1a Types of slope failures – translational slideFig.7.1b Types of slope failures – rotational slideDetached landslide deposit(滑动面)Sliding mass (滑体)Fig.7.2 Plane Translational slide with no water tableFig.7.3 Plane Translational slide with water tableFig.7.4 Total stress analysiszb WN T zb WN’ T Ud O。
最全水利水电工程专业英语词汇
水利水电工程专业英语词汇施工总平面布置(施工总体布置) construction general layout施工组织Consruction Programming施工组织设计construction planning施工坐标系（建筑坐标系) construction coordinate system湿化变形soaking deformation湿润比percentage of wetted area湿润灌溉wetting irrigation湿室型泵房wet-pit type pump house湿陷变形系数soaking deformation coefficient湿陷起始压力initial collapse pressure湿陷系数（湿陷变形系数) coefficient of collapsibility湿周wetted perimeter十字板剪切试验vane shear test石袋honeycomb时均流速time average velocity时均能量time average energy时效硬化（老化）age hardening (ageing) 时针式喷灌系统(中心支轴自走式系统) central pivot sprinkler system实测放大图surveyed amplification map实腹柱solid column实际材料图primitive data map实时接线分析real time connection analysis 实时控制real—time control实时数据和实时信息real time data and real time information实体坝solid dike实体重力坝solid gravity dam实物工程量real work quantity实验站experimental station实用堰practical weir示流信号器liquid-flow annunciator示坡线slope indication line示误三角形error triangle示踪模型tracer model事故failure （accident）事故备用容量reserve capacity for accident 事故低油压tripping lower oil pressure 事故音响信号emergency signal （alarmsignal）事故运行方式accident operation mode事故闸门emergency gate事故照明accident lighting事故照明切换屏accident lightingchange-over panel势波potential wave势流potential flow势能potential energy势涡（自由涡）potential vortex视差parallax视差法测距（基线横尺视差法）subtense method with horizontal staff视差角parallactic angle视准线法collimation line method视准轴（照准轴) coolimation axis试验处理treatment of experiment试验端子test terminal试验项目Testing item试验小区experimental block试运行test run试运行test run收敛测量convergence measurement收敛约束法convergence—confinement method收缩断面vena—contracta收缩缝(温度缝) contraction joint (temperature joint）收缩水深contracted depth手动[自动]复归manual ［automatic] reset 手动[自动］准同期manual ［automatic］precise synchronization手动调节manual regulation手动控制manual control手动运行manual operation手工电弧焊manual arc welding首曲线（基本等高线）standard contour首子午线（本初子午线,起始子午线）prime meridian受油器oil head枢纽布置layout of hydroproject疏浚dredging输电系统transmission system输电线transmission line输入功率试验input test输沙量sediment runoff输沙率sediment discharge输水钢管steel pipe for water conveyance 输水沟conveyance ditch输水建筑物water conveyance structure输水渠道water conveyance canal鼠道mole drains鼠道犁mole plough鼠笼型感应电动机squirrel cage induction motor竖井定向测量shaft orientation survey竖井贯流式水轮机pit turbine竖井联系测量shaft connection survey竖井排水drainage well竖井式进水口shaf tintake竖轴弧形闸门radial gate with vertic alaxes 数字地面模型digital terrain model（DTM)数字化测图digitized mapping数字通信digital communication数字图像处理digital image processing数字仪表digital instrument甩负荷load dump （load rejection，load shutdown）甩负荷试验load-rejection test (load—shutdowntest）双层布置double storey layout双调节调速器dual-regulation governor双扉闸门double-leaf gate双回线double-circuit line双击式水轮机cross flow turbine,Banki turbine双极高压直流系统bipolar HVDC system双金属标bimetal bench mark双列布置double row layout双母线接线double—bus connection双曲拱坝double curvature arch dam双曲拱渡槽double curvature arch aqueduct 双室式调压室double—chamber surge shaft 双吸式离心泵double-suction pump双向挡水人字闸门bidirectional retaining mitre gate 水泵［水泵水轮机的水泵工况]的反向最大稳态飞逸转速steady state reverse runaway speed of pump水泵比转速specific speed of pump水泵并联扬程曲线head curve of parallel pumping system水泵参数与特性Parameters and characteristics of pump水泵串联扬程曲线head curve of series pumping system水泵的最大［最小］输入功率maximum ［minimum］input power of pump水泵电动机机组Motor-pump unit水泵反常运行pump abnormal operating水泵工况（抽水工况) pump operation水泵工作点（水泵工况点) pump operating point水泵供水water feed by pump水泵机械效率mechanical efficiency of pump 水泵机组pump unit水泵类型Classification of pumps水泵零部件Components of pumps水泵流量pump discharge水泵容积效率volumetric efficiency of pump 水泵输出功率output power of pump水泵输入功率（水泵轴功率）input power of pump水泵水力效率hydraulic efficiency of pump水泵水轮机Pump-turbine水泵无流量输入功率no—discharge power of pump水泵效率pump efficiency水泵扬程(水泵总扬程) total head of pump 水泵站Pumping Station水泵装置pump system水锤（水击）water hammer水锤泵站hydrauli cram pump station水锤波(水击波) wave of water hammer水锤波波速wave velocity of water hammer 水电站Hydroelectric Station水电站（水力发电站）Hydroelectric station （hydroelectric power station）水电站保证出力firm power，firm output水电站厂房(发电厂房) power house水电站厂房的类型Types of power house of hydroelectric station水电站出力power output of hydropower station水电站出力和发电量Power and energy output of hydropower station水电站的水头、流量、水位Waterhead，discharge，water lever of hydropower station水电站发电成本generation cost of hydropower station水电站发电量energy output of hydropower station水电站建筑物hydroelectric station structure 水电站经济指标Economie index of hydropower station水电站类型Types of hydroelectric station水电站引用流量quotative discharge of hydropower station水电站装机容量installed capacity of hydropower station水电站自动化automation of hydroelectric station水跌hydraulic drop水动力学Hydrodynamics水斗bucket水斗式水轮机(贝尔顿式水轮机) pelton turbine水工建筑物hydraulic structure水工建筑物的类别及荷载Classification and load of hydraulic structures水工建筑物级别grade of hydraulic structure 水工金属结构及安装Metal Structures and Their Installation水工隧洞hydraulic tunnel水工隧洞Hydraulic tunnels水工隧洞构造Components of hydraulic tunnel水工隧洞类型Classification of hydraulic tunnels水管冷却pipe cooling水柜water pool水环真空泵liquid ring pump水灰比water-cement ratio 水窖(旱井）water callar（dry wall)水静力学Hydrostatics水库并联运用operation of parallel-connected resertvoir水库测量reservoir survey水库串联运用operation of serial—connected reservoirs水库调度reservoir operation水库调度图graph of reservoir operation水库回水变动区fluctuating back water zone of reservoir水库浸没reservoir immersion水库控制缓洪controlled flood retarding水库库底清理cleaning of reservoir zone水库泥沙Reservoir sediment水库泥沙防治Prevention of sediment水库年限ultimate life of reservoir水库渗漏reservoir leakage水库水文测验reservoir hydrometry水库塌岸bank ruin of reservoir水库特征库容Characteristic capacity of reservoir水库特征水位Characteristic level of reservoir 水库泄空排沙sediment releasing by emptying reservoir水库蓄清排浑clear water impounding and muddy flow releasing水库淹没补偿compensation for reservoir inundation水库淹没处理Treatment of reservoir inundation水库淹没处理范围treatment zone of reservoir inundation水库淹没界线测量reservoir inundation line survey水库淹没区zone of reservoir inundation水库淹没实物指标material index of reservoir inundation水库异重流density current in reservoir水库异重流排沙sediment releasing by density current水库诱发地震reservoir induced earthquake 水库淤积Sediment deposition in reservoir水库淤积测量reservoir accretion survey水库淤积极限limit state of sediment deposition in reservoir水库淤积平衡比降equilibrium slope of sediment deposition in reservoir水库淤积上延（翘尾巴) upward extension of reservoir deposition水库淤积纵剖面longitudinal profile of deposit in reservoir水库滞洪排沙flood retarding and sediment releasing水库自然滞洪free flood retarding水冷式空压机water-cooled compressor水力半径hydraulic radius水力冲填hydraulic excavation and filling水力冲填坝hydraulic fill dam水力冲洗式沉沙池hydraulic flushing sedimentation basin水力粗糙度hydraulic roughness水力粗糙区hydraulic roughness region水力共振hydraulic resonance水力光滑区hydraulic smooth水力机械Hydraulic Machinery水力机械与电气设备HYDRAULIC MACHINERY AND ELECTRIC EQUIPMENT水力机组hydropower unit水力机组测试Measurement and test for hydropower unit水力机组的安装和试运行Installation and starting operation of hydropower unit水力机组调节系统Regulating system of hydropower unit水力机组辅助系统Auxiliary system for hydropower unit水力开挖hydraulic excavation水力坡降(水力比降) hydraulic slope (energy gradient）水力破裂法(水力致裂法）hydro fracturing method水力侵蚀(水蚀) water erosion水力学Hydraulics水力要素（水力参数) hydraulic elements水力指数hydraulic exponent水力自动闸门hydraulic operating gate水力最优断面optimal hydraulic cross section 水利工程经营管理management and administration of water project水利计算Computation of water conservancy 水利区划zoning of water conservancy水利枢纽hydroproject水利水电工程等别rank of hydroproject水利水电工程规划PLANNING OF HYDROENGINEERING水利水电工程技术术语标准Standard of Technical Terms on Hydroengineering水利水电工程勘测SURVEY AND INVESTIGATION FOR HYDROENGINEERING 水利水电工程施工CONSTRUCTION OF HYDRAULIC ENGINEERING水量分布曲线water distribution curve水流动力轴线（主流线) dynamic axis of flow 水流连续方程continuity equation of flow水流流态State of flow水流阻力和能头损失Flow resistance and head loss水轮泵站turbine-pump station水轮发电机Hydraulic generator水轮发电机hydraulic turbine—driven synchronous generator （hydro-generator) 水轮发电机组Hydraulic turbine—generator unit水轮发电机组hydraulic turbine—generator unit水轮机hydraulic turbine,water turbine水轮机［水泵]额定流量rated discharge of turbine［pump]水轮机安装Installation of hydraulic turbine 水轮机安装高程setting of turbine水轮机保证出力guaranteed output of turbine 水轮机比转速specific speed of turbine水轮机参数和特性Turbine parameters and turbine characteristics水轮机层turbine storey (turbine floor)水轮机的机械效率mechanical efficiency of turbine水轮机的容积效率volumetric efficiency of turbine水轮机的水力效率hydraulic efficiency of turbine水轮机调节系统turbine regulating system水轮机调节系统静特性试验static characteristic test of regulation system of hydraulic turbine水轮机调速器turbine governor水轮机额定输出功率（水轮机额定出力）rated output of turbine水轮机飞逸转速runaway speed of turbine水轮机工况（发电工况）turbine operation 水轮机空载流量no-load discharge of turbine 水轮机类型Classification of turbines水轮机零、部件Components of hydraulic turbine水轮机流量turbine discharge水轮机模型试验model test of turbine水轮机磨蚀与振动Erosion and vibration of hydraulic turbine水轮机气蚀系数cavitation factor of turbine，cavitation coefficient of turbine水轮机设计水头design head of turbine水轮机试运行Test runof hydraulic turbine水轮机室turbine casing水轮机输出功率（水轮机出力）turbine output 水轮机输入功率turbine input power水轮机水头(水轮机净水头）turbine net head 水轮机吸出水头损失suction head loss of turbine水轮机效率turbine efficiency水轮机压力管道（高压管道）penstock水轮机引水室turbine flume水轮机主轴turbine main shaft水轮机最大输出功率（水轮机最大出力）maximum output of turbine水轮机最高效率maximum efficiency of turbine水面曲线water surface profile水面蒸发量evaporation from water surface 水能waterpower，hydropower水能计算hydropower computation水能开发方式Types of hydropower development水能利用Water power utilization 水能利用规划waterpower utilization planning水能资源（水力资源）waterpower resources，hydropower resources水泥比表面积specific surface of cement水泥罐cement silo水泥水化热hydration heat of cement水泥体积安定性soundness of cement水平底坡horizontal slope水平地质剖面图geological plan水平度levelness水平沟horizontal ditches水平阶地horizontal terraces水平位移工作点operative mark of horizontal displacement水平位移观测horizontal displacement observation水平位移基点datum mark of horizontal displacement水生态学hydrobiology水头water head水头损失head loss水头预想出力expected power，expected output水土保持soil and water conservation水土保持工程措施Soil and water conservation works水土保持规划Planning of soil and water conservation水土保持林业措施Afforestation measures for soil and water conservation水土流失Soilandwaterloss水土流失（土壤侵蚀) soil erosion（soil and waterloss）水位water stage (water level）水位、流速、流量Water stage，flow velocity, flow discharge水位传导系数coefficient of water level conductivity水位调节装置water level regulator水位计water—level gauge水位流量关系曲线stage-discharge relation curve水位信号water-level indicating signal水位站water stage gauging station水文测验hydrometry水文测站hydrometrical station水文测站和站网Hydrometrical station and network水文地质Hydrogeology水文地质基础Basichydrogeology水文地质试验Hydrogeologicaltest水文地质图hydrogeological map水文调查hydrological investigation水文分析计算Hydrological analysis and computation水文观测hydrological observation水文观测Hydrological observation and measurement水文过程线hydrograph水文核技术nuclear technology in hydrology 水文计算Hydrologic computation水文计算及水文预报Hydrological Computation and Forecasing水文空间技术space technology in hydrology 水文模型hydrological model水文年鉴hydrological almanac（hydrological yearbook）水文频率曲线hydrological frequency curve 水文手册hydrological handbook水文统计hydrological statistics水文图集hydrological atlas水文遥测技术hydrological telemetering technology水文要素hydrological data水文预报Hydrological forecast水文站hydrometrical station水文站网hydrological network水文资料整编hydrological data processing水系(河系，河网) hydrographic net(river system)水下爆破under water blasting水下地形测量underground topographic survey水下混凝土浇筑underwater concreting水下接地网under water earthed network水压力hydraulic pressure水跃hydraulic jump 水跃长度length of hydraulic jump水跃高度height of hydraulic jump水跃函数hydraulic jump function水跃消能率coefficient of energy dissipation of hydraulic jump水运动学Hydrokinematics水运动学及水动力学Hydrokinematics and hydrodynamics水闸sluice (barrage）水闸类型Classification of sluices水闸组成部分Components of sluice水质water quality水质标准water quality standard水质监测站water quality monitoring station 水质评价water quality assessment水质污染Water quality pollution水质预报water quality forecast水中起动starting in water水中起动力矩starting torque in water水柱water column水坠坝sluicing siltation earth dam水准测量leveling水准点benchmark水准路线leveling line水准器分划值（水准器角值，水准器格值）scale value of level水准网平差adjustment of leveling network 水准仪(水平仪) level水准仪与经纬仪Leveland theodolite水资源water resources水资源规划water resources planning水资源开发利用Development and utilization of water resources水资源开发利用water resources development税金tax顺坝longitudinal dike (training dike)顺坡(正坡）positive slope顺行波advancing downstream wave顺序控制系统sequential control system顺直型河流straight river瞬动电流instantaneous acting current瞬发雷管（即发雷管) instantaneous blasting cap瞬时沉降(弹性沉降，初始沉降,形变沉降）initial settlement瞬时单位线instantaneous unit hydrograph 瞬时电流速断保护(无时限电流速断保护）instantaneous over current cut-off protection瞬时流速instantaneous velocity瞬态法finite increment method死库容(垫底库容）dead storage死区dead band死水位minimum pool level(dead water level）松动爆破loosening blasting (crumbling blasting）松方loose measure松散系数bulk factor素混凝土（无筋混凝土) plain concrete素图simple map速动时间常数promptitude time constant速度环量velocity circulation速度三角形velocity triangle速凝（瞬时凝结) quick set (flash set）速凝剂accelerator塑料导爆管（传爆管) plastic primacord tube 塑限（塑性限度，塑性界限含水量) plastic limit 塑性铰plastic hinge塑性指数plasticity index溯源冲刷[淤积］backward erosion ［deposition］算术平均粒径arithmetic mean diameter算术平均水头arithmetic average head算术平均效率arithmetic average efficiency 随动系统servo system随动系统不准确度inaccuracy of servosystem 随机波random wave随机性水文模型（非确定性水文模型) stochastic hydrological model碎部点（地形特征点）detail point碎裂结构clastic structure碎屑结构clastic texture隧洞衬砌tunnel lining隧洞导流tunnel diversion隧洞渐变段tunnel transition section隧洞开挖tunnel excavation 隧洞排水tunnel drainage隧洞钻孔爆破法(隧洞钻爆法）drill-blast tunneling method损失容积（死容积）lost volume缩限(收缩界限）shrinkage limit锁坝closure dike锁定装置dog device (latch device,gate lock device)锁锭装置locking device （checking device）它励（它激) separate excitation塔式进水口tower intake踏面rolling face台车式启闭机platform hoist台阶结构面step structural plane台阶掘进法heading and bench method坍落度slump坍落拱collapse arch探槽exploratoryt rench探洞exploratory adit探井exploratory shaft探坑exploratory pit碳素钢(碳钢) carbon steel塘堰pond掏槽孔(掏槽眼）cut hole套管casing pipe套闸(双埝船闸) double dike lock特大暴雨extraordinary rainstorm特大洪水extraordinary flood特高压(特高电压）ultra-high voltage (U。
某水库边坡稳定性分析与加固治理 水利工程等专业本科学位论文
本科生毕业论文某水库边坡稳定性分析与加固治理The some reservoir side slope Stability analysis and Reinforceto manage指导教师：学院：专业：年级：论文提交日期：答辩日期：某水库边坡稳定性分析与加固治理摘要边坡稳定性问题一直是岩土边坡一个重要研究内容。
它涉及水电工程、铁道工程、公路工程、矿山工程等诸多工程领域，能否正确评价其稳定性直接关系到建设的资金投入和人民的生命财产安全。
因此，如何设计经济、安全可靠的边坡工程和分析评价天然边坡的稳定性，其重要意义显得越发突出。
边坡稳定性分析与加固方法很多，不同的方法又各具特点，有一定的适用条件。
如何根据具体的边坡工程地质条件及分析目的与精度要求，合理有效地选用与之相适应的边坡稳定性分析与加固方法，是一项很重要的工作。
从边坡工程研究发展历程可见，边坡稳定性研究发展的过程，同时又是一个边坡稳定性分析与加固方法不断发展的过程。
本文首先介绍了边坡稳定性分析方法的发展现状和目前各种边坡加固措施，以及分析了影响边坡稳定性的各种因素，对目前边坡工程中常用的各种稳定性分析方法进行了系统的总结，阐述了它们各自的主要原理、特点和适用范围，着重探讨了目前工程上最为常用的条分法。
最后结合某水库边坡工程，对其进行稳定性分析及加固方案设计，总结边坡防护与加固的基本原则、基本思路以及常用的边坡防护加固方法，并进行了综合比较。
关键词：边坡；稳定性分析；防护加固The some reservoir side slope Stability analysis and Reinforceto manageABSTRACTThe slope stability problem has been the rock soil slope an importance research contents.It involves electrician's distance of water, the railroad engineering, the highway engineering, the mineral mountain engineering waits many engineering realms, can be right to evaluate its stability to relate to the funds devotion of the construction and the life property safety of the peoples directly.Therefore, how design the stability that the economy, the safe and dependable slope engineering and analysis evaluates the natural slope , its important meaning seem to be more and more outstanding.The slope stability analysis with reinforce the method a lot of, different method again each characteristics, have to certainly apply the condition.How according to the concrete slope engineering geology condition, analyze the purpose and accuracies request in a specific way, reasonable choose availably use with it mutually adapt of the slope stability analysis with reinforce the method, is a very important work.From the slope engineering research development process it is thus clear that, the process of the slope stability research development, at the same time again is a slope stability analysis with reinforce the method to develop continuously of process.This text introduces the development present condition of the slope stability analysis method to reinforce the measure with various slope currently first, and analyzed stable various factor of the influence slope , to currently the slope engineering in various in common use stability analyzes the summary that the method carried on the system, elaborating them each from of main principle, characteristics and apply the scope, emphasize to inquiry into the engineering to ascend the most in common use to divide the method bine a reservoir slope engineering finally, as to it's carry on the stability analysis and reinforce the project design, tally up the slope protection with reinforce of basic principle, basic way of thinking and the in common use slope protection reinforce the method, and carried on the comprehensive comparison.Key words：slope；stability analysis；protecting and reinforcement目录1前言 (1)1.1 课题设计的意义 (1)1.2 边坡稳定性分析方法的发展现状 (1)1.3 边坡加固措施综述 (3)1.4 本文的主要内容 (5)2 边坡稳定性的影响因素 (5)2.1 地质构造 (5)2.2 地层岩性 (5)2.3 汇水域及地表、地下水文 (6)2.4 地震作用 (7)2.5 小结 (8)3 边坡稳定性的计算分析方法 (8)3.1 边坡稳定性的数值计算分析 (8)3.1.1 边坡稳定性的有限元分析 (9)3.1.2 边坡稳定性的离散元分析 (10)3.2 边坡稳定性的极限平衡分析 (10)3.2.1 边坡滑动稳定性的Sarma法 (11)3.2.2 边坡滑动稳定性的条分法 (11)3.3 小结 (12)4 边坡稳定性分析程序 (13)4.1 Stab及Emu边坡分析软件的程序说明 (13)4.1.1 Stab软件的程序说明 (13)4.1.2 Emu软件的程序说明 (15)4.2 理正岩土边坡分析软件程序说明 (17)4.3 Flac3D软件有限元分析 (18)4.4 ANSYS软件非线性有限单元法分析 (19)5 某水库边坡稳定性分析与加固治理 (20)5.1 工程概况 (20)5.2 设计工程地质概况 (20)5.3 软件在边坡工程中的稳定性分析 (21)5.3.1 计算成果分析 (21)5.3.2 稳定性分析 (22)5.4 边坡的加固治理 (22)5.4.1 加固方法的比较 (22)5.4.2 加固措施 (23)5.5 小结 (25)6 结论及建议 (25)参考资料 (27)致谢 (28)附录 (29)某水库边坡稳定性分析与加固治理1前言1.1 课题设计的意义边坡稳定性问题一直是岩土边坡一个重要研究内容。
锦屏一级水电站左岸高边坡变形监测及稳定性分析
水利水电技术(中英文)㊀第52卷㊀2021年第4期梁靖,裴向军,罗路广,等.锦屏一级水电站左岸高边坡变形监测及稳定性分析[J].水利水电技术(中英文),2021,52(4):180-185.LIANG Jing,PEI Xiangjun,LUO Luguang,et al.Deformation monitoring and stability analysis of left bank highslope at Jinping I Hydro-power Station[J].Water Resources and Hydropower Engineering,2021,52(4):180-185.锦屏一级水电站左岸高边坡变形监测及稳定性分析梁㊀靖1,裴向军1,罗路广1,刘㊀明1,杨静熙2(1.成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都㊀610059;2.中国电建集团成都勘测设计研究院有限公司,四川成都㊀610072)收稿日期:2020-08-06基金项目:国家重点研发计划(2016YFC0401908);国家创新性集体基金(41521002);川藏铁路重大工程风险识别与对策研究项目(2019YFG0460)作者简介:梁㊀靖(1995 ),男,硕士研究生,主要从事地质灾害评价与预测研究㊂E-mail:370918252@通信作者:裴向军(1970 ),男,教授,博士研究生导师,博士,从事地质灾害㊁工程边坡稳定性评价与工程治理研究㊂E-mail:peixj0119@ 摘㊀要:受复杂地质条件和高陡地形等因素影响,锦屏一级水电站左岸高边坡在水库蓄水运行阶段仍出现持续缓慢变形,其稳定性问题受到高度关注㊂为此,基于现场调查与最新监测结果数据,从监测反馈和地质角度揭示了边坡变形破坏特征及机制,并以此分析边坡稳定性㊂分析结果表明:左岸边坡的表观与深部累计位移变形仍呈现缓慢增长趋势,但历经变形调整后速率有一定减缓,可将变形机制归纳为 上部持续倾倒-深部张裂-表部锁固体松弛-下部与坝体协调 ;目前左岸高边坡受库水位影响而变形仍未收敛,但变形较为平稳且无异常现象,满足安全控制标准;由于边坡长期变形发展趋势的影响因素复杂,尚存不确定性,仍需持续监测以及进一步研究㊂关键词:锦屏一级水电站;高边坡;变形监测;稳定性分析doi :10.13928/ki.wrahe.2021.04.019开放科学(资源服务)标志码(OSID ):中图分类号:TV 223.13文献标志码:A文章编号:1000-0860(2021)04-0180-06Deformation monitoring and stability analysis of left bank highslope at Jinping I Hydropower StationLIANG Jing 1,PEI Xiangjun 1,LUO Luguang 1,LIU Ming 1,YANG Jingxi 2(1.State Key Laboratory of Geo-Hazards Prevention and Geo-Environment Protection,Chengdu University of Technology,Chengdu ㊀610059,Sichuan,China;2.PowerChina Chengdu Engineering Corporation Limited,Chengdu㊀610072,Sichuan,China)Abstract :Under the influences from the factors,plicated geological condition,high-steep terrain,etc.,the continu-ous deformation of the left bank at Jinping I Hydropower Station still occurs during the impounding and operation phase,and then its stability is highly concerned.Therefore,the characteristics and mechanism of the deformation and failure of the slope are revealed herein from the aspects of the monitoring feedback and the geological condition therein based on the in situ investigation and the latest monitoring data,from which the slope stability is analyzed.The analysis result shows that the apparently and deeply accumulated displacement deformation of the left bank slope still exhibits a slowly increasing trend,but the deformation rate is slowed to a certain extent after experiencing the relevant deformation adjustment,while the deformation mechanism can be sum-marized as continuous toppling of the upper part deeply tension-cracking surface locking solid body relaxation the coor-dination between the lower part and the dam body .At present,the deformation is still not converged under the influence of res-ervoir water,but it becomes relatively stable without any abnormal phenomena,thus can meet the relevant safety control stand-ards.As the influencing factors of the long-term deformation development trend of the slope are complicated with some梁㊀靖,等//锦屏一级水电站左岸高边坡变形监测及稳定性分析uncertainties,the relevant continuous monitoring and further study concerned are still necessary to be carried out.Keywords :Jinping I Hydropower Station;high slope;deformation monitoring;stabilityanalysis图1㊀左岸边坡分区及表观监测布置Fig.1㊀Left bank slope zoning and apparent monitoring layout1㊀工程概况㊀㊀锦屏一级水电站为雅砻江中下游的控制性巨型水库梯级,具有边坡开挖高㊁规模大以及稳定条件复杂等特点㊂左岸坝肩岩层产状为N14ʎ~36ʎE /NWø31ʎ~46ʎ,属典型的反倾坡体㊂坝区出露杂谷脑组(T 2-3Z )灰白色㊁灰黑色大理岩与千板岩,岩层厚度变化大㊁变形强㊂边坡开挖揭露有f2㊁f5㊁f8㊁f42-9等断层㊁煌斑岩脉(X)㊁深部拉裂结构面及长大陡倾溶蚀裂隙㊂由此可见,左岸边坡不良地质体发育,有必要对其变形及稳定性进行研究㊂长期以来,大型水电工程高边坡的稳定性评价主要以理论分析㊁专家评估㊁监测系统及数值模拟为主[1-3]㊂赵明华等[4]对小湾电站高边坡监测与分析,揭示了边坡变形原因及稳定性发展趋势㊂张世殊等[5]通过归纳溪洛渡水电站库岸边坡的倾倒变形体特征与蓄水之间的相关性,提出了其在蓄水作用下的进一步发展演化机制㊂朱继良等[6]研究发现高边坡开挖与变形具有同步性,并将变形可归纳为:浅表松弛型㊁协调渐变型和回弹错动型㊂同时,孙元等[7]也以某城区开挖支护边坡为例,结合监测数据预测了其变形趋势㊂裴向军[8]㊁黄志鹏等[9]研究了锦屏一级水电站左岸边坡开挖与蓄水期间的变形响应特征㊂而李程等[10]将三维电子罗盘测量法应用于边坡变形监测,为研究边坡变形及破坏模式提供了新思路㊂此外,沈辉等[11]基于非线性有限元分析,对蓄水后高边坡变形及稳定性开展了数值模拟分析㊂本文基于锦屏一级电站已有的各阶段研究成果,结合最新监测资料收集㊁变形调查以及针对性的排查分析等手段,深入研究左岸高边坡的影响因素㊁变形特征及机理等,并宏观定性地评价边坡稳定性,为复杂坝肩加固处理效果评价㊁工程运行阶段高边坡稳定性及大坝安全评估提供基础资料和建议㊂2㊀监测布置㊀㊀锦屏一级左岸边坡开挖以来,变形速率虽逐渐减缓,但监测显示浅表与深部的变形仍未收敛㊂本文选取截止2020年2月的表观变形监测与深部拉裂监测进行变形与稳定性分析㊂如图1所示,表观变形监测共设立80个观测墩,可分别监测水平和垂向位移变梁㊀靖,等//锦屏一级水电站左岸高边坡变形监测及稳定性分析形㊂此外,根据坡体结构及变形特征将左岸边坡划分为6个宏观变形区,此处选对坝肩影响较大的1 4区监测成果数据进行分析㊂深部变形监测的目的是分析深部拉裂缝在边坡开挖和蓄水运行期的变形响应,并用于评价边坡的安全稳定性㊂左岸边坡布设深部石墨杆收敛计监测仪器的平洞有PD42㊁PD44㊁PD54及1915mL2C排水洞,此处选取数据采集较完整的PD44㊁PD42进行分析(见图2),布置测点共计33个,其中PD44有13个,PD42有20个,监测点主要记录坡内横河向(水平)位移㊂3㊀稳定性监测成果分析3.1㊀表观变形监测㊀㊀如图3(a)所示,变形1区总位移累计曲线显示,自蓄水以来的位移增长较为显著,最新监测数据表明,变形量值仍呈缓慢增长趋势,最大累计位移可达220mm,最小为50mm㊂同时,蓄水对总位移曲线的变形趋势影响较小,仅在增长过程中表现出一定程度波动性,而在运行期后其波动幅度越来越小,变形速率也有不断减缓(见表1)㊂进一步深入分析可知,该区总体以下沉变形为主,呈现上部变形大㊁下部变形小的特点,这也与上部倾倒变形体的变形规律吻合㊂如图3(b)所示,2区变形整体小于1区,但蓄水后仍以下沉变形为主,局部呈上抬变形,且与库水升降具有较强相关性,其变形累计位移最大约105mm,曲线在增长的同时呈现出一定程度的波动,并同水位升降保持着同步性㊂在经历初蓄期增长后,运行期的变形速率有所降低(见表1),运行4期平均㊀㊀㊀㊀速率为0.38mm/月㊂细化来看,运行期库水位下降阶段变形速率较大,而上升阶段则相对较小㊂如图3(c)所示,变形3区总体以向上游偏河床沉降变形为主,变形比高位倾倒变形区要小,受库水位升降的影响较明显,该区的总位移累计变化集中在70~120mm,呈现缓慢增长趋势,但随时间增长也表现出一定波动性,整体变形速率呈现持续降低(见表1)㊂如图3(d)所示,4区变形相对最弱,该区的总位移累计变形集中在37~74mm,变形速率仅为0.21 mm/月(见表1)㊂该区运行期总体较平稳,体现出 波动-调整 的特征,但总位移调整幅度远小于水平位移,说明其水平向位移受库水位波动影响较大㊂进一步分析监测资料发现,该区蓄水期后高高程部位的竖向变形以沉降为主,而低高程部位主要为抬升㊂3.2㊀深部变形监测㊀㊀对于布置在平洞内的深部变形监测点,统计各测点的累计变形监测成果如图4所示㊂由图4可见, PD42与PD44平洞反映的深部变形以水平方向位移为主,整体位移矢量方向均由坡内指向坡外㊂从揭示的深部变形与蓄水动态关系来看,左岸平硐PD42累计位移量值达到42mm[见图4(a)],其中上支洞变形量较大,下支洞在蓄水后的变形已趋于收敛,除初蓄期有变形激增外,运行期内影响均不显著㊂PD44受煌斑岩脉X㊁断层f42-9以及坡体内部系列小断层和深拉裂缝影响,累计位移量值最大达到85mm[见图4(b)],平洞122m以外洞段对首次蓄水响应明显,对运营期蓄水还处于适应调整阶段㊂进一步分析可知:①初期蓄水阶段,特别是高水位首次降低时引起的变形明显突跃;②对低高程部㊀㊀㊀㊀图2㊀边坡深部变形监测布置Fig.2㊀Deep deformation monitoring layout梁㊀靖,等//锦屏一级水电站左岸高边坡变形监测及稳定性分析图3㊀表观变形区总位移累计曲线Fig.3㊀Cumulative total displacement curve of apparent deformationarea图4㊀平洞测点相对洞底的累计位移曲线Fig.4㊀Cumulative displacement curve of adit表1㊀变形区不同时期平均位移速率变化Table 1㊀The average displacement rate in different periodsin the deformation region变形分区不同时期平均位移速率/mm㊃月-1初蓄期运行1期运行2期运行3期运行4期1㊀区 1.070.840.690.670.62㊀区0.980.670.630.440.383㊀区0.720.670.620.460.364㊀区0.240.550.570.450.21㊀㊀注:初蓄期为2014-08-24 2015-09-28;运行1期为2015-09-292016-09-28;运行2期为2016-09-29 2017-09-28;运行3期为2017-09-29 2018-09-28;运行4期为2018-09-29 2019-09-28位,库水影响体现在高水位时的位移量增加明显;③对高高程平硐,运行期水位的季节性变化对其变形影响明显减弱㊂综合表观与深部的变形监测成果及特点,可知左岸边坡在现阶段的变形仍在缓慢增长,局部变形态势还未收敛㊂经过初期蓄水的变形调整后,运行期变形速率呈现一定缓减㊂可以看出,左岸边坡的稳定性仍需基于监测数据从机制与稳定性来深入分析㊂4㊀变形机制与稳定性分析4.1㊀变形破坏模式及机制㊀㊀考虑到边坡地质结构㊁变形分区特征以及蓄水等因素影响,认为左岸边坡的长期变形总体属于蓄水动梁㊀靖,等//锦屏一级水电站左岸高边坡变形监测及稳定性分析态变化与工程结构荷载下产生,受 反倾层状结构+深部裂缝+外倾缓带分割 控制的变形调整响应㊂结合各区变形特征,将变形模式概括为 上部持续倾倒-深部张裂-表部锁固体松弛-下部与坝体协调 ,并初步归纳出变形机制:(1)上部持续倾倒主要是软硬互层的岩性组合㊁陡倾的反向坡体结构及开口线以上浅部坡体卸荷所共同导致,2区是受开挖卸荷以及f5㊁f8断层所控制㊂同时,库水位升降又使得岩体及软弱带不断发生饱水和干湿循环,导致力学性质弱化,进而持续引发倾倒变形㊂(2)深部张裂主要为f42-9断层上盘㊁煌斑岩脉X深部裂缝的持续张拉变形,加之蓄水后软弱层带软化导致3区深部变形持续增加㊂此外,库水位下降导致深部累计位移曲线有较大幅度的抬升,初步分析为坡体内部受到向外的渗透压力而产生水平向位移,且在软弱结构以及深拉裂缝处变形更为明显㊂(3)表部锚墙的整体锁固作用使得回弹变形不断向深部传递,同时锁固的部分坡体浅表也会整体性侧向松弛变形,主要表现为间次性地向外鼓胀㊁岩脉或小断层等陡倾结构面附近呈现集中性拉裂㊂(4)下部与坝体协调一是指边坡自身变形对大坝的加载作用,二是指坝肩推力对边坡的反作用㊂这种协调是动态发展的,即有利于坝体应力改善,也会威胁大坝安全㊂主要表现为在库水位抬升产生的推力使得部分坡体压密与抬升,下降时推力减小又导致坝体应力加载状况改变,呈现出随水位动态变化的趋势,这也是4区的变形机制所在㊂4.2㊀稳定性评价㊀㊀从宏观上看,左岸开挖边坡运行期的持续变形是在蓄水新常态下由特定地质结构控制的一种自适应调整变形㊂开口线以上高位倾倒变形区(1区)变形尚未收敛,拱肩槽上游开挖边坡(2区)仍处于变形调整期,潜在 大块体 区域(3区)的表观㊁多点位移计等监测成果显示无整体趋向的滑移现象,坝肩边坡㊁拱坝抗力体边坡(4区)则处于相对稳定状态㊂此外,抗剪洞与围岩之间变形协调过程已近完成,但f42-9断层软弱带的垂向压缩-侧向扩容过程受边坡与坝体协调作用影响,存在周期性活动,这也是深部持续变形的主要原因㊂实际监测成果与理论分析表明,锦屏一级左岸高边坡受库水位影响而处于变形调整期,边坡岩体继续向坡外变形,尚未收敛,但变形较为平缓,且无异常变形情况,变形量级满足安全控制标准,边坡整体较稳定㊂5㊀结㊀论㊀㊀针对锦屏一级水电站左岸高边坡的变形与稳定性问题,本文结合最新变形监测成果从地质角度进行了宏观定性评价㊂结果表明:(1)左岸边坡受库水位影响仍处于变形调整期㊂其中1区㊁2区㊁3区及深部平洞变形速率虽处于较低水平,但累积位移仍缓慢增长,无明显收敛趋势㊂与此相反,4区变形速率则趋于平稳,整体较为稳定㊂(2)左岸边坡的长期潜在破坏模式主要有三类,即大块体的整体性块体失稳㊁沿主控性底滑面的剪切失稳及部分区域剪断岩体而呈圆弧式的滑动失稳㊂并将变形机制概括为 上部持续倾倒-深部张裂-表部锁固体松弛-下部与坝体协调 ㊂(3)从整体变形上看,左岸边坡受库水位影响仍处于蓄水运营调整阶段,变形尚未收敛㊂边坡岩体持续变形,但变形较为平稳且无异常现象,现阶段左岸边坡岩体表面变形总体稳定,但仍需持续监测与关注㊂参考文献(References):[1]㊀吕建红,袁宝远,杨志法,等.边坡监测与快速反馈分析[J].河海大学学报(自然科学版),1999,27(6):98-102.LU Jianhong,YUAN Baoyuan,YANG Zhifa,et al.Study on slope monitoring and quick feedback[J].Journal of hohai university(natu-ral science edition),1999,27(6):98-102.[2]㊀王成虎,何满潮,郭啟良.水电站高边坡变形及强度稳定性的系统分析研究[J].岩土力学,2007,28(S1):581-585.WANG Chenghu,HE Manchao,GUO Qiliang.Systematic analysis of deformation and strength stability of high 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外文翻译--水利水电工程施工
外文翻译--水利水电工程施工英文原文:Water Resources and Hydropower Engineering Construction Design Layout[Key words] construction layout Fuzzy multiple attribute decision making Water Resources and Hydropower Construction [Abstract] Analysis of affecting factors of the construction layout program characteristics that people value in identifying these indicators fuzzy constraints are difficult to give exact values, while decision-making process has been one of psychological, subjective will and the work experience and other aspects influence decision-making process and therefore there is certainly ambiguity 1, Water Resources and Hydropower Engineering Construction Layout Factors Construction advantages and disadvantages of the general layout scheme, involving many factors, from different angles to evaluate the evaluation factors generally have two categories, qualitative factors, and quantitative factors of a classQualitative factors are mainly: 1Favorable production, easy to administer, facilitate the degree of life; 2During the construction process, the degree of co-ordination; 3The principal impact of construction and operation; 4Meet the security, fire, flood prevention,environmental protection requirements; 5Temporary Works and the combination of permanent works and so onIndicators are mainly quantitative factors; 1Site preparation earthwork quantity and cost; 2. The extent of use of earth excavation; 3Temporary works of construction work quantity and cost; 4Workload and a variety of materials, transport costs; 5Size and cost of land acquisition; 6Made to the area to field, the recovery or recycling construction fees As the construction is construction planning layout content, is that people under work experience, combined with engineering data on the occurrence of a future prediction aboutTherefore, both qualitative factors, and the quantitative factors, there is uncertaintyWe know that the uncertainty of two different forms; one is uncertain whether the incident occurred in 11 random, the event itself the state of uncertainty 11 ambiguityRandomness is an external cause in general uncertain, but ambiguity is an inherent uncertainty of the structureFrom the information point of view, the randomness involves only the amount of information, while the ambiguity is related to the meaning of informationWe can say that ambiguity is more profound than the randomness, the uncertainty more generally, especially in the subjective understanding of areas of role ambiguity is much more important than the role of randomnessRandom people for a lot of research has been carried out, achieved fruitful results; while ambiguity was ongoing and in-depth knowledge and research in theAllpeople involved in the system, carried out by people planning, feasibility studies, evaluation of decision-making, design and management, and therefore, can not ignore the objective world of things in the human brain, one by one to reflect the uncertainty of ambiguity, it is an objective difference intermediate division caused by the transition of a kind of uncertaintyConstruction Layout Design is no exception, in the arrangement of construction there are a large number of objective fuzzy factorsFor example, the construction of facilities, coordination between the levels of "good" and "general" is an accurate value can not be describedTherefore, the arrangement can not ignore or avoid the construction of the fuzziness existing in the process, but should be objective and deal with ambiguity of this objective, understand the rules for people planning, demonstration, evaluation and decision, design and management to provide a scientific basis and methods As the construction layout of the content involved in more programs fuzzy factors exist, the traditional construction arrangement he considered the existence of ambiguity, but in decision-making process has fuzzy information precision, not a real fuzzy optimizationTherefore, the program should focus on optimization of fuzzy factors into account, the ambiguity should be reflected in the decision-making on the index, index weightsFor quantitative indicators, mainly the amount and cost of the project issues, its value can be found in engineering materials and design documents to determine by calculation,the results are the values of the parameters and experienceAs every engineer's understanding of things is not the same experience in a certain range of parameter changes, the results also in a certain rangeFor qualitative indicators, according to experts, engineering experience, through expert scoring method, set the value of statistics to determineSuch subjective factors, the knowledge structure and decision-making preferences play a major roleBut in practice, due to the complexity of objective things and the people's thinking on the use of fuzzy concept, to describe with precision the number becomes very difficult, but with "some", "left" and the like get fuzzy concept to describe the more reasonableDetermine the weights of evaluation indexes, there are many mathematical ways to determine the accurate calculationWe know, for different projects, in the same factors, their importance is not the same, then the mathematical model is difficult to fully reflect the actual situation, the help of experts in engineering experience must be judged Since the existence of the above ambiguity, avoid or ignore the ambiguity is unscientific, incompletePrevious index value that decision-making, decision weights for programs for determining the value of the preferred method, there is bound to sidedness and limitationsAs technology develops, people are increasingly demanding of precision, the object of study become more complicated, as complicated to some degree after the meaning of the precise cognitive declines and the appropriatefuzzy but accurateHere, the introduction of fuzzy mathematical tools, the use of modern fuzzy multiple attribute decision making theory, Fuzzy multiple attribute decision making model, can exist for people to consider the ambiguity of the objective, to provide strong support for rational decision-making2, Water Resources and Hydropower Engineering Construction Design Layout Construction Layout as a focus of the system around the concrete layout of the temporary structuresThere are 1All kinds of storage, stockpile and Spoil; 2Mechanical repair system; 3Metal structure, mechanical and electrical equipment and construction equipment installed base; 4Wind, water and electricity supply systems; 5Other construction plant, such as steel processing, wood processing, prefabricated factory; 6Office and living space, such as offices, laboratories, dormitories, hospitals, schools, etc.; 7Fire safety facilities and other, such as fire stations, guard, and security cordon soAt this time, various types of temporary structures should be put forward, the construction of facilities furnished a list of partial pressure, their area, building area and volume of construction and installation; on fertilization with an estimate of land acquisition, land area and the proposed land use plan, the study to reclaiming land in the use of the measures, site preparation earthwork volume calculations, the integrated cut and fill balance of the proposed excavation of the use of effective planning Construction offacilities in order to avoid conflict between the layouts, construction of facilities in the analysis of adjacency relations, is to analyze the relationship between the construction of facilities, strength of correlation and relationshipUsually based on the adjacency relationship, consider the construction schedule, construction strength, facilities operation and logisticsAnalysis of the size and layout of the construction of facilities present at the location of the ground between the site controlled the indicators are: 1The scale of construction facilities layout, the main considerations to meet the construction requirements of the case, the construction of facilities, capacity and layout area2Foundation bearing capacity of the construction of facilities to consider geology, slope stability and so on3Hydrological requirements and construction guide closure of the case, consider the different construction periods, flood, water table, water level changes in the construction site layout planning of construction restrictions and impact4. The height difference logistics constraints, considering logistics and vertical elevation gradient lines, logistics of import and export5Construction of the distance between these facilities and restrictions, mainly refers to the construction of facilities necessary for running the minimum operating radius, the minimum limit transportation question, minimum import and export logistics, construction and facilities, the safety distance between6Constructionsite area of internal and external traffic conditions, construction equipment, consider the minimum safe height and width of the transport, building materials inside the transport requirements To be concrete system facilities arranged in a prominent position, so that interference by the other facilities as small as possible, the need for construction of facilities at this time analysis of the relationship between the adjacent, as many facilities for Hydropower Construction, different facilities have a clear focus on functionality, such as depots, gas stations, etc., if not for the neighbor relations analysis, because the construction of facilities for the inter-functional conflict, construction and project management to bring incalculable damage and safety hazards buried References: [1] Lu Yu Mei editor of the Three Gorges Dam Construction [M]. Beijing: China Electric Power Press, 2003[2] Wei-Jun Zhu, Zhang Xiaojun and so the overall layout design of the Three Gorges Project Construction [J]. The people of the Yangtze River, 2001.32 10 :4-5译文:水利水电工程施工的布置方案设计[关键词]施工布置模糊多属性决策水利水电施工[论文摘要]分析施工布置方案的影响因素特点,指出人们在确定这些指标值时受到模糊性因素的限制很难给出精确值,同时决策过程还受到人们心理、主观意愿和工作经验等多方面的影响,因而决策过程也必然存在模糊性。
水利水电工程专业外文翻译--边坡稳定性
外文翻译Stability of Slopes1.1 Introduction Gravitational and seepage forces tend to cause instability in natural slopes, in slopes of embankments and earth dams. The most important types of slope failure arc illustrated in Fig.1.1. In rotational slips the shape of the failure surface in section may be a circular are or a non-circular curve. In general, circular slips are associated with homogeneous soil conditions and non-circular slips with non- homogeneous conditions. Translational and compound slips occur where the form of failure surface is influenced by the presence of an adjacent stratum is at a relatively shallow depth bellow the surface of the slope: the failure surface tends to be plane and roughly parallel to the slope. Compound slips usually occur where the adjacent stratum is at greater depth, the failure surface consisting of curved and plane sections.Figure 1.1 Type of slope failureIn practice, limiting equilibrium methods are used in the analysis of slope stability. It is considered that failure is on the point of occurring along an assumed or a known failure surface. The shear strength required to maintain a condition of the limiting equilibrium is compared with the available shear strength of the soil, giving the average factor safety along the failure surface. The problem is considered in two dimensions, conditions of plane strain being assumed. It has been shown that two-dimensional analysis gives a conservative result for a failure on a three-dimensional (dish-shaped) surface.Figure 1. 2 The φu =0 analysis1.2 Analysis for the Case of φu =0The analysis, in term of total stress ,covers the case of a fully-saturated clay under undrained conditions, i.e. for the condition immediately after construction. Only moment equilibrium is considered in the analysis. In section, the potential failure surface is assumed to be a circle arc. A trial failure surface (centre O, radius and length L a ) is shown in Fig 1.2.Potential instability is due to the total weight of the soil mass(W per unit length) above the failure surface. For equilibrium the shear strength which must be mobilized along the failure surface is expressed as: τm =f F τ=Cu Fwhere F is the factor of safety with respect to shear strength. Equation momentabout O:Wd=Cu FL a r F=u a C L r Wd (1.1) The moments of any additional forces must be taken into account. In the event of a tension crack developing, as shown in Fig1.2,the arc length L a is shortened and a hydrostatic force will act normal to the crack if the crack fills with water. It is necessary to analyze the slope for a number of trial failure surfaces in order that the minimum factor of safety can be determined.Example 1.1A 45°slope is excavated to a depth of 8m in a deep layer of unit weight 19kN/m 3: the relevant shear strength parameters are c u =65kN/m 3 and φu =0.Determine the factor of safety for the trial surface specified in Fig1.3.In Fig1.3, the cross-sectional area ABCD is 70m 2.The weight of the soil mass=70×19=1330m 2.The cent roid of ABCD is 4.5m from O.The angle AOC is 89.5°and radius OC is 12.1m.The arc length ABC is calculated as 18.9m.The factor of safety is given by:F=u a C L r Wd=6518.912.11330 4.5⨯⨯⨯6518.912.11330 4.5⨯⨯⨯ =2.48This is the factor of safety for the trial failure surface selected and is not necessarily the minimum factor of safety.Figure 1.3 example 1.11.3 The φ-Circle MethodThe analysis is in terms of total stress. A trial failure surface , a circular arc (centre o, radius r) is selected as shown in Fig 1.4.If the shear strength parameters are c u and φu ,the shear strength which must be mobilized for equilibrium is:τm =f Fτ=l ∑ =c m +tan m σφ Figure 1.4 The φ-circle methodWhere F is the factor of safety with respect to shear strength .For convenience the following notation is introduced:c m =u cc F (1.2) tan m φ=tan u F φφ (1.3) it being a requirement that:F C =F φ=FAn element ab, of length l, of the failure surface is considered, the element being short enough to be approximated to a straight line. The forces acting on ab (per unit dimension normal to the section) are as follows:(1) the total normal force 1σ;(2) the component of shearing resistance c m l;(3) the component of shearing resistance 1σtan m φ.If each force c m l along the failure surface is split into components perpendicular and parallel to the chord AB, the perpendicular components sum to zero and the sum of the parallel components is given by:C=c m L c (1.4) where L c is the chord length AB. The force C is thus the resultant, acting parallel to the chord c m l. The line of application of the resultant force C can be determined by taking moments about the centre O, then:C r c =r m c l ∑i.e.c m L c r c =rc m L awhere La=l ∑ is the arc length AB.Thus,r c =a CL L r (1.5) The resultant of the forces 1σ and 1σtan m φ on the element ab acts at angle m φ to the normal and is the force tangential to a circle, centre O, of radius r sin m φ: this circle is referred to as the φ-circle. The same technique was used in Chapter 5.The overallresult (R) for the arc AB is assumed to be tangential to the φ-circle. Strictly, the resultant R is tangential to a circle of radius slightly greater than r sin m φ but the error involved in the above assumption is generally insignificant.The soil mass above the trial failure surface is in equilibrium under its totalweight (W) and the shear resultants C and R. The force W is known in magnitude and direction; the direction only of the resultant C is known. Initially a trial value of F φ is selected and the corresponding value of m φ is calculated from equation1.3.For equilibrium the line of application of the resultant R must be tangential to the φ-circle and pass though the point of intersection of the forces W and C. The force diagram can then be drawn, from which the value of C can be obtained .Then:c m =CC L andF C =Cu Cm It is necessary to repeat the analysis at least three times, starting with different values of F φ.If the calculated values of F C are plotted against the corresponding values of F φ,the factor of safety corresponding to the requirement F C =F φ can be determined .The whole procedure must be repeated for a series of trial failure surfaces in order that the minimum factor of safety is obtained.For an effective stress analysis the total weight W is combined with the resultant boundary water force on the failure mass and the effective stress parameters c ′and φ′used.Based on the principle of geometric similarity, Taylo r （1.13）published stability coefficients for the analysis of homogeneous slopes in terms of total stress. For a slope of height H the stability coefficients for the analysis of homogeneous slopes in terms of total stress. For a slope of height H the stability coefficient (N s ) for the failure surface along which the factor of safety is a minimum is:N s =u C F Hγ (1.6) Values of N s , which is a function of the slope angle β and the shear strength parameter u φ,can be obtained from Fig 1.5.For u φ=0,the value of N s also depends on the depth factor D, where DH is the depth to a firm stratum.Firm stratumFigure 1.5 Taylo r ′s coefficients.In example 1.1, β=45°, u φ=0,and assuming D is large, the value of N s is 0.18.Then from equation 1.6:F=s Cu N H γ = 650.18198⨯⨯ =2.37Gibson and Morgenste r n 〔1.4〕published stability coefficients for slopes in normally-consolidated clays in which the untrained strength c u (u φ=0) varies linearly with depth.Figure 1.6 Example 1.2Example 1.2An embankment slope is detailed in Figure 1.6.Fir the given failure surface. Determine the factor of safety in terms of total stress using the φ-circle method. The appropriate shear strength parameters are c u =15kN/m 2 and u φ=15°: the unit weight of soil is 20 kN/m 2.The area ABCD is 68 m 2 and the centroid (G) is 0.60m from the vertical through D. The radius of the failure arc is 11.10m.The arc length AC is 19.15 m and the chord length AC is 16.85m.The weight of the soil mass is:W=68×20=1360 k N/mThe position of the resultant C is given by:r c =a CL L r = 19.1516.85×11.10 Now:m φ=tan -1(tan15F φ) Trial value of F φ are chosen, the corresponding values of r sin m φ are calculated and the φ-circle drawn shown in Fig.1.6.The resultant C(for any value of F φ) acts in a directions parallel to the chord AC and at distance r c from O. The resultant C(for any value F φ) acts in a direction parallel to the chord AC and at distance r c from O. The forces C and W intersect at point E. The resultant R, corresponding to each value of F φ, passes through E is tangential to the appropriate φ-circle. The force diagrams are drawn and the values of C determined.The results are tabulated below.If F c is plotted against F φ(Fig.1.6) it is apparent that:F=F C =F φ=1.431.4 The Method of SlicesIn this method the potential failure surface, in section, is against assumed to be a circle arc with centre O radius r. The soil mass (ABCD) above a trial failure surface(AC) is divided by vertical planes into series of slices of width b, as shown in Fig.1.7. The base of each slice is assumed to be a straight line. For any slice the inclination of the base to the horizontal is α and the height, measured on the centerline, is h. The factor of safety is defined as the ratio of the available shear strength (f τ) to the shear strength (m τ) which must be mobilized to maintain a condition of limiting equilibrium. i.e.F=f mττ The factor of safety is taken to be the same for each slice, implying that there must be mutual support between the slice. i.e. forces must act between the slices.The forces (per unit dimension normal to the section) acting on a slice are listed below.(1) The total weight of slice, W=γbh (γsat where appropriate)(2) The total normal force on the base, N. In general this force has two components.The effective normal force N′ (equal to σ′l ) and the boundary water force ul, where u is the pore water pressure at the center of the base and l is the length of the base.(3) The shear force on the sides, T=m τl.(4) The total normal forces on the sides,E 1 and E 2.(5) The shear forces on the sides, X 1 and X 2.Any external forces must also be included in the analysis.The problem is statically indeterminate and in order to obtain a solution assumptions must be made regarding the inter-slice forces E and X: the resulting solution for factor of safety is not exact.Considering moments about O, the sum of the moments of the shear forces T on the failure arc AC must equal the moment of the weight of the soil mass ABCD. For any slice the lever arm of w is r sin α, therefore:Tr ∑=sin rW α∑Figure 1.7 The method of slices.Now,T=m τl=f l F τ ∵ f l F τ∑=sin W α∑∴ F=sin fl W τα∑∑ For an analysis in terms of effective stress:F=(tan )sin c l W σφα'''+∑∑ or, F= tan sin c La N W φα'''+∑∑ （1.7） where L a is the arc length AC. Equation 1.7 is exact but approximations are introduced in determining the forces N′. For a given failure arc the value of F will depend on the way in which the forces N′ are estimated.The Fellenius SolutionIn the solution it is assumed that for each slice the resultant of the inter-slice forces is zero. The solution involves resolving the forces on each slice normal to the base, i.e.:cos N W ul α'=-Hence the factor of safety in terms of effective stress ( equation 1.7 ) is given by: F=tan (cos )sin c La W ul W φαα''+-∑∑ (1.8)The components cos W α and sin W α can be determined graphically for each slice. Alternatively, the value of α can be measured or calculated. Again, a series of trial failure surfaces must be chosen in order to obtain the minimum factor of safety. This solution underestimates the factor of safety :the error, compared with more accurate methods of analysis, is usually within the range of 5-20﹪.For an analysis in terms of total stress the parameters c u and φu are used and the value of u in equation 1.8 is zero. If φu =0 the factor of safety is given by:F=sin u a c L W α∑(1.9)As N ′does not appear in equation 1.9 an exact value of F is obtained.The Bishop Simplified SolutionIn this solution it is assumed that the resultant forces on the sides of the slices are horizontal, i.e.X 1-X 2=0For equilibrium the shear force on the base of any slice is:T= 1(tan )c l N Fφ'''+ Resolving forces in the vertical direction:cos cos sin tan sin c l N W N ul F Fαααφα''''=+++ ∴ tan sin (sin cos )/(cos )c l N W ul F F φαααα'''=--+ (1.10) It is convenient to substitute:l= sec b αFrom equation 1.7, after some rearrangement:1sec [{()tan }]tan tan sin 1F c b W ub W Fαφαφα''=+-'+∑∑ (1.11) The pore water press can be related to the tota l ‘fill pressure ’ at any point by means of the dimensionless pore press ratio , defined as:u u r hγ= (1.12) (sat γ where appropriate )For any slice,/u u r W b =Hence equation 1.11 can be written: 1sec [{(1)tan }]tan tan sin 1u F c b W r W Fαφαφα''=+-'+∑∑ (1.13) As the factor of safety occurs on both sides of equation 1.13 a process of successive approximation must be used to obtain a solution but convergence is rapid. The method is very suitable for solution on the computer. In the computer program the slope geometry can be made more come complex, with soil strata having different properties and pore pressure conditions being introduced.In most problems the value of the pore pressure ratio u r is not constant overthe whole failure surface but, unless there are isolates regions of high pore pressure, an average value (weighted on an area basis) is normally used in design. Again, the factor of safety determined by this method is an underestimate but the error is unlikely to exceed 7﹪ and in most cases is less than 2﹪.Spencer [1.12] proposed a method of analysis in which the resultant inter-slice forces are parallel and in which both force and moment equilibrium are satisfied.Spencer showed that the accuracy of the Bishop simplified method, in which only moment equilibrium is satisfied, is due to the insensitivity of the moment equation to the slope of the inter-slice forces.Dimensionless stability coefficients for homogeneous slopes, based on equation 1.13, have been published by Bishop and Morgenstern[1.3]. It can be shown that for a given slope angle and given soil properties the factor of safety varies linearly with u r and can thus be expressed as:u F m nr =- (1.14)where m and n are the stability coefficients m and n are functions of β,φ', the dimensionless number /c h γ' and the depth factor D.Example 1.3Using the Fellenius method of slices, determined the factor of safety in terms of effective stress of the slope shown in Fig.1.8 for the given failure surface. The distribution of pore water pressure along the failure surface is given in the figure. The unit weight of the soil is 20 kN/m 3 and the relevant shear strength parameters are c '=10kN/m 2 and φ'=29°.The factor of safety is given by equation 9.8. The soil mass is divided into slices 1.5m wide. The weight(W) of each slice is given by:20 1.530/W bh h hkN m γ==⨯⨯=The height h for each slice is set off bellow the centre of the base and the normal and tangential components cos h α and sin h α respectively are determined graphically, as shown in Fig.1.8.Then:cos 30cos W h αα=andsin 30sin W h αα=Figure 1.8 Example 1.3.The arc length (L a ) is calculated as 14.35m. The results are tabulated below:cos 3017.50525/W kN m α=⨯=∑sin 308.45254/W kN m α=⨯=∑(cos )525132.8392.2/W ul kN m α-=-=∑tan (cos )sin ac L W ul F W φαα''+-=∑∑ (1014.35)(0.554393.2)254⨯+⨯= 1.5 Analysis of a Plane Translational SlipIt is assumed that potential failure surface is parallel to the surface of the slope and is at a depth that is small compared with the length of the slope. The slope can then be considered as being of infinite length, with end effects being ignored. The slope is inclined at angle β to the horizontal and the depth of the failure plane z, as shown in section in Fig.1.9. The water table is taken to be parallel to the slope at a height of mz(0＜m ＜1)above the failure plane. Steady seepage is assumed to be taking place in a direction parallel to the slope. The forces on the sides of any vertical slice are equal and opposite and the stress conditions are the same at every point on the failure plane.Figure 1.9 Plane translational slip.In terms of effective stress, the shear strength of the soil along the failure plane is:()tan f c u τσφ''=+-and the factor of safety is:f F ττ= The expressions for σ, τ and u are as follows:2{(1)}cos sat m m z σγγβ=-+{(1)}sin cos sat m m z τγγββ=-+2cos w u mz γβ=The following special cases are of interest. If c '=0 and m=0(i.e. the soil between the surface and the surface plane is not fully saturated), then:tan tan F φβ'= （1.15） If c '=0 and m=1(i.e. the water table conditions with the surface of the slope),then: sat tan tan F γφγβ''==If should be noted that when c '=0 the factor of safety is independent of the depth z. If c ' is greater to zero, the factor of safety is a function of z, and β may exceed φ' provided z is less than a critical value.For a total stress analysis the shear strength parameters u c and u φ are used and the value of u is zero.A long natural slope in fissured overconsolidated clay is inclined at 12° to the horizontal. The water table is at the surface and seepage is roughly parallel to the slope. A slip has developed on a plane parallel to the surface at a depth of 5m.The saturated unit weight of the clay is 20 kN/m 3. The peak strength parameters arec '=10kN/m 2 and φ'=26°; the residual strength parameters are r c '=0 and r φ'=18°. Determine the factor of safety along the slip plane(a) in terms of the peak strength parameters, (b) in terms of the residual strength parameters.With the water table at the surface (m=1), at any point on the slip plane:2cos sat z σγβ=22205cos 1295.5/kN m =⨯⨯=sin cos sat z τγββ=2205sin12cos1220.3/kN m =⨯⨯⨯=2cos w u z γβ=229.85cos 1246.8/kN m =⨯⨯=Using the peak strength parameters:()tan f c u τσφ''=+-210(48.7tan 26)33.8/kN m =+⨯=Then the factor of safety is given by:33.8 1.6620.3f F ττ=== Using the residual strength parameters, the factor of safety can be obtained from equation 1.16:tan tan r sat F γφγβ''=10.2tan180.7820tan12=⨯= 1.6 General Methods of AnalysisMorgenstern and Price[1.8] developed a general analysis in which all boundary and equilibrium conditions are satisfied and in which the failure surfacemay be any shape, circle ,non-circle and compound. The soil mass above the failure plane is divided into sections by a number of vertical planes and the problem is rendered statically determinate by assuming a relationship between the forces E and X on the vertical boundaries between each section. This assumption is of the form:()X f x E λ= (1.17)where f(x) is an arbitrary function describing the pattern in which the ratio X/E varies across the soil mass and λ is obtained as part of the solution along with the factor of safety F. The values of the forces E and X and the point of application of E can be determined at each vertical boundary. For any assuming function f(x) it is necessary to examine the solution in detail to ensure that it is physically reasonable (i.e. no shear failure or tension must be implied within the soil mass above the failure surface). The choice of the function f(x) does not appear to influence the computed value of F by more than about 5﹪ and f(x)=1 is a common assumption.The analysis involves a complex process of iteration for the value of λand F, described by Morgenstern and Price [1.9], and the use of a computer is essential.Bell [1.15] proposed a method of analysis in which all the conditions of equilibrium are satisfied and the assumed failure surface may be of any shape. The soil mass is divided into a number of vertical slices and statical determinacy is obtained by means of an assumed distribution of normal stress along the failure surface. Thus the soil mass is considered as a free body as is the case in the φ-circle method.Sarma [1.16] developed a method, based on the method of slices, in which the critical earthquale accelaration required to produce a condition of limiting equilibrium is determined. An assumed distribution of vertical inter-slice forces is used in the analysis. Again, all the conditions of equilibrium are satisfied and the assumed failure surface may be of any shape. The static factor of safety is the factor by which the shear strength of the soil must be reduced such that the critical acceleration if zero.The use of a computer is also essential for the Bell and Sarma methods and all solutions must be checked to ensure that they are physically acceptable.1.7 End-of-Construction and Long-Term StabilityWhen a slope is formed either by excavation or by the construction of an embankment the changes in total stress result in changes in pore water pressure in the vicinity of the slope and, in particular, along a potential failure surface. Prior toconstruction the initial pore water pressure(u 0) at any point is governed either by a static water table level or by a flow net for conditions of steady seepage. The change in pore water pressure at any point is is given theoretically by equation 4.17 or 4.18. The final pore water pressure, after dissipation of the excess pore water pressure, is governed by the static water table level or the steady seepage flow net for the final conditions after construction.If the permeability of the soil is low, a considerable time will elapse before any significant dissipation of excess pore water pressure will have taken place. At the end of construction the soil will be virtually in the undrained condition and a total stress analysis will be relevant. In principle an effective stress analysis is also possible for the end of construction condition using the pore water pressure (u) for this condition, where :o u u u =+∆However, because of its greater simplicity, a total stress analysis is generally used. It should be realised that the same factor of safety will not generally be obtained from a total stress and an effective stress analysis of the end-of-construction condition. In a total stress and an effective stress analysis of the end-of-construction condition. In a total stress analysis it is implied that the pore water pressures are those for a failure condition: in an effective stress analysis the pore water pressures used are those predicted for a non-failure condition. In the long-term, the fully-drained condition will be reached and only an effective stress analysis will be appropriate.If, on the other hand, the permeability of the soil is high, dissipation of excess pore water pressure will be largely complete by the end of construction. An effective stress analysis is relevant for all conditions with values of pore water pressure being obtained from the static water table level or the appropriate flow net.Pore water pressure may thus be an independent variable, determined from the static water table level or from the flow net for conditions of steady seepage, or may be dependent on the total stress changes tending to cause failure.It is important to identify the most dangerous condition in any practical problem in order that the appropriate shear strength parameters are used in design. Excavated and Natural Slopes in Saturated ClaysEquation 4.17, with B=1 for a fully-saturated clay, can be rearranged as follows:131311()()()22u A σσσσ∆=∆+∆+-∆-∆ (1.18) For a typical point P on a potential failure surface(Fig.9.10) the first term in equation 1.18 is negative and the second term will also be negative if the value ofA is less than 0.5. Overall, the pore water pressure change u ∆ is negative. The effect of the rotation of principal stress directions is neglected. As dissipation proceeds the pore pressure increases to the final value as shown in Fig.1.10. The factor of safety will therefore have a lower value in the long-term, when dissipation is complete, than at the end of construction.Figure 1.10 Pore press pressure dissipation and factor of safety (AfterBishop and [1.2])Residual shear strength is relevant to the long-term stability of slopes in over consolidated fissured clays. A number of cases are on record in which failures in this type of clay have occurred long after dissipation of excess pore water pressure hade been completed. Analysis of these failures showed that the average shear strength at failure was bellow the peak value. In clays of this type it is suspected that large strains can occur locally due to the presence of fissures, resulting in the peak strength being reached, followed by a gradual decrease towards the residual value. The development of large local strains can lead eventually to a progressive slope failure. Fissures may not be the only cause of progressive failures: there is considerable nonuniformity of shear stress along a potential failure surface and local overstressing may initiate progressive failure. It should be realised, however, that the residual strength is reached only after a considerable slip movement has taken place and the strength relevant to first-time ′ slips lies between the peak and residual values. Analysis of failures in natural slopes in overconsolidated fissured clays has indicated that the residual shear strength is ultimately attained, probably as a result of successive slipping.1.8 Stability of Earth DamsIn the design of earth dams the factor of safety of both slopes must be determined as possible for the most critical conditions. For economic reasons an unduly conservative design must be avoided. In the case of the upstream slope the most critical stages are at the end of construction and during rapid drawdown of the reservoir level. The critical stages for the downstream slope are at the end of construction and during steady seepage when the reservior is full. The pore water pressure distribution at any stage has a dominant influence on the factor of safetyand in large earth dams it is common practice to install a piezometer system so that the actual pore water pressures can be measured at any stage and compared with the predicted values used in design(provided an effective stress analysis has been used) . Remedial action can then be taken if the factor of safety , based on the measured values, is considered too bellow.(a) End of ConstructionThe construction Period of an earth dam is likely to be long enough to allow partial dissipation of excess pore water pressure before the end of construction, especially in a dam with internal drainage. A total stress analysis, therefore, would result in too conservative a design. An effective stress analysis is preferable, using predicted values of r u .The pore pressure (u) at any point can be written as:0u u u =+∆where 0u is the initial value and u ∆ is the change in pore water pressure undrained conditions. In terms of the change in total major principal stress:01u u B σ=+∆Then:01u u r B h hσγγ∆=+ If it is assumed that the increase in total major principal stress is approximately equal to the fill pressure along a potential failure surface, then:0u u r B hγ=+ (1.19) The soil is partially saturated when compacted, therefore the initial pore water pressure (u 0) is negative. The actual value of u 0 depends on the placement water content, the higher the water content, the closer the value of u 0 to zero. The value of B also depends on the placement water content, the higher the water content, the higher the value of B . Thus for an upper bound:u r B = (1.20) The value of B must correspond to the stress conditions in the dam. Equations1.19 and 1.20 assume no dissipation during construction. A factor of safety as low as 1.3 may be acceptable at the end of construction provided there is reasonable confidence in the design data.If high values of u r are anticipated, dissipation of excess pore water pressure。
水利专业中外语对比翻译2
河北工程大学中外文翻译中外语对比翻译学院水电学院专业农业水利工程班级农水1001姓名徐伟学号100270133importance of waterWater is best known and most abundant of all chemical compounds occurring in relatively pure form on the earth’s surface.Oxygen,the most abundant chemical element,is present in combination with hydrogen to the extent of89percent in water.Water covers about three fourths of the earth's surface and permeates cracks of much solid land.The Polar Regions(原文polar regions)are overlaid with vast quantities of ice,and the atmosphere of the earth carries water vapor in quantities from0.1percent to2percent by weight.It has been estimated that the amount of water in the atmosphere above a square mile of land on a mild summer day is of the order of50,000tons.All life on earth depends upon water,the principal ingredient of living cells.The use of water by man,plants,and animals is universal.Without it there can be no life.Every living thing requires water.Man can go nearly two months without food,but can live only three or four days without water.In our homes,whether in the city or in the country,water is essential for cleanliness and health.The average American family uses from65,000to75,000gallons of water per year for various household purposes.Water can be considered as the principal raw material and the lowest cost raw material from which most of our farm produces is made.It is essential for the growth of crops and animals and is a very important factor in the production of milk and eggs.Animals and poultry, if constantly supplied with running water,will produce more meat,more milk,and more eggs per pound of food and per hour of labor.For example,apples are87%water.The trees on which they grow must have watered many times the weight of the fruit.Potatoes are75%water.To grow an acre of potatoes tons of water is required.Fish are80%water.They not only consume water but also must have large volumes of water in which to k is88%water.To produce one quart of milk a cow requires from3.5to5.5quarts of water.Beef is77%water.To produce a pound of beef an animal must drink many times that much water.If there is a shortage of water,there will be a decline in farm production,just as a shortage of steel will cause a decrease in the production of automobiles.In addition to the direct use of water in our homes and on the farm,there are many indirectways in which water affects our lives.In manufacturing,generation of electric power, transportation,recreation,and in many other ways,water plays a very important role.Our use of water is increasing rapidly with our growing population.Already there are acute shortages of both surface and underground waters in many locations.Careless pollution and contamination of our streams,lakes,and underground sources has greatly impaired the quality of the water which we do have available.It is therefore of utmost importance for our future that good conservation and sanitary measures be practiced by everyone.In nature,water is constantly changing from one state to another.The heat of the sun evaporates water from land and water surfaces,this water vapor(a gas),being lighter than air, rises until it reaches the cold upper air where it condenses into clouds.Clouds drift around according to the direction of the wind until they strike a colder atmosphere.At this point the water further condenses and falls to the earth as rain,sleet,or snow,thus completing the hydrologic cycle.The complete hydrologic cycle,however,is much more complex.The atmosphere gains water vapor by evaporation not only from the oceans but also from lakes,rivers,and other water bodies,and from moist ground surfaces.Water vapor is also gained by sublimation from snowfields and by transpiration from vegetation and trees.Water precipitation may follow various routes.Much of the precipitation from the atmosphere falls directly on the oceans.Of the water that does fall over land areas,some is caught by vegetation or evaporates before reaching the ground,some is locked up in snowfields or ice-fields for periods ranging from a season to many thousands of years,and some is retarded by storage in reservoirs,in the ground,in chemical compounds,and in vegetation and animal life.The water that falls on land areas may return immediately to the sea as runoff in streams and rivers or when snow melts in warmer seasons.When the water does not run off immediately it percolates into the soil.Some of this groundwater is taken up by the roots of vegetation and some of it flows through the subsoil into rivers,lakes,and oceans.Because water is absolutely necessary for sustaining life and is of great importance in industry men have tried in many ways to control the hydrologic cycle to their own advantage. An obvious example is the storage of water behind dams in reservoirs,in climates where there are excesses and deficits of precipitation(with respect to water needs)at different times in the year.Another method is the attempt to increase or decrease natural precipitation by injecting particles of dry ice or silver iodide into clouds.This kind of weather modification has had limited success thus far,but many meteorologists believe that a significant control ofprecipitation can be achieved in the future.Other attempts to influence the hydrologic cycle include the contour plowing of sloping farmlands to slow down runoff and permit more water to percolate into the ground,the construction of dikes to prevent floods and so on.The reuse of water before it returns to the sea is another common practice.Various water supply systems that obtain their water from rivers may recycle it several times(with purification)before it finally reaches the rivers mouth.Men also attempt to predict the effects of events in the course of the hydrologic cycle.Thus, the meteorologist forecasts the amount and intensity of precipitation in a watershed,and the hydrologist forecasts the volume of runoff.The first hydraulic project has been lost in the mists of prehistory.Perhaps some prehistoric man found that pile of rocks across a stream would raise the water level sufficiently to overflow the land that was the source of his wild food plants and water them during a drought. Whatever the early history of hydraulics,abundant evidence exists to show that the builders understood little hydrology.Early Greek and Roman writings indicated that these people could accept the oceans as the ultimate source of all water but could not visualize precipitation equaling or exceeding stream-flow.Typical of the ideas of the time was a view that seawater moved underground to the base of the mountains.There a natural still desalted water,and the vapor rose through conduits to the mountain tops,where it condensed and escaped at the source springs of the streams.Marcus Vitruvius Pollio(ca.100B.C.)seems to have been one of the first to recognize the role of precipitation as we accept it today.Leonardo da Vinci(1452-1519)was the next to suggest a modern view of the hydrologic cycle,but it remained for Pierre Perrault(1608-1680)to compare measured rainfall with the estimated flow of the Seine River to show that the stream-flow was about one-sixth of the precipitation.The English astronomer Halley(1656-1742)measured evaporation from a small pan and estimated evaporation from the Mediterranean Sea from these data.As late as1921, however,some people still questioned the concept of the hydrologic cycle.Precipitation was measured in India as early as the fourth century B.C.,but satisfactory methods for measuring stream-flow were a much later development.Frontinus,water commissioner of Rome in A.D.97,based estimates of flow on cross-sectional area alone without regard to velocity.In the United States,organized measurement of precipitation started under the Surgeon General of the Army in1819,was transferred to the Signal Corps in1870, and finally,in1891,to a newly organized U.S.Weather Bureau,renamed the National Weather Service in1970.Scattered stream-flow measurements were made on the Mississippi River as early as1848,but a systematic program was not started until1888,when the U.S.GeologicalSurvey undertook this work.It is not surprising,therefore,that little quantitative work in hydrology was done before the early years of the twentieth century,when men such as Hortan, Mead,and Sherman began to explore the field.The great expansion of activity in flood control, irrigation,soil conservation,and related fields which began about1930gave the first real impetus to organized research in hydrology,as need for more precise design data became evident.Most of today’s concepts of hydrology date from1930.Hydrology is used in engineering mainly in connection with the design and operation of hydraulic structures.What flood flows can be expected at a spillway or highway culvert or in a city drainage system?What reservoir capacity is required to assure adequate water for irrigation or municipal water supply during droughts?What effects will reservoirs,levees,and other control works exert on flood flows in a stream?These are typical of questions the hydrologist is expected to answer.Large organization such as federal and state water agencies can maintain staffs of hydrologic specialists to analyze their problems,but smaller offices often have insufficient hydrologic work for full-time specialists.Hence,many civil engineers are called upon for occasional hydrologic studies.It is probable that these civil engineers deal with a larger number of projects and greater annual dollar volume than the specialists do.In any event,it seems that knowledge of the fundamentals of hydrology is an essential part of the civil engineer’s training.Hydrology deals with many topics.The subject matter as presented in this book can be broadly classified into two phases:data collection and methods of analysis.Chapter2to6deals with the basic data of hydrology.Adequate basic data are essential to any science,and hydrology is no exception.In fact,the complex features of the natural processes involved in hydrologic phenomena make it difficult to treat many hydrologic processes by rigorous deductive reasoning.One can not always start with a basic physical law and from this determine the hydrologic result to be expected.Rather,it is necessary to start with a mass of observed facts, analyze these facts,and from this analysis to establish the systematic pattern that governs these events.Thus,without adequate historical data for the particular problem area,the hydrologist is in a difficult position.Most countries have one or more government agencies with responsibility for data collection.It is important that the student learn how these data are collected and published,the limitations on their accuracy,and the proper methods of interpretation and adjustment.Typical hydrologic problems involve estimates of extremes not observed in a small data sample,hydrologic characteristic at locations where no data have been collected(such locations are much more numerous than sites with data),or estimates of the effects of man’s actions onthe hydrologic characteristics of an area.Generally,each hydrologic problem is unique in that it deals with a distinct set of physical conditions within a specific river basin.Hence,quantitative conclusions of one analysis are often not directly transferable to another problem.However,the general solution for most problems can be developed from application of a few relatively basic concepts.Of all the earth’s water97%is found in the oceans,2%in glaciers and only1%on land.Of this1%almost all(97%)is found beneath the surface and called sub-surface or underground water.Most of this water eventually finds its way back to the sea either by underground movement or by rising into surface streams and lakes.These vast underground water deposits provide much needed moisture for dry areas and irrigated districts.Underground water acts in similar ways to surface water,also performing geomorphic work as an agent of gradation.Even though man has been aware of sub-surface water since earliest times,its nature, occurrence,movement and geomorphic significance have remained obscure.Recently,however, some answers have been found to the perplexing questions about underground water’s relationship to the hydrological cycle.Since the days of Vitruvius at the time of Christ,many theories have been presented to explain the large volume of water underneath the earth’s surface.One theory was that only the sea could provide such large quantities,the water moving underground from coastal areas. Vitruvius was the first to recognize that precipitation provided the main source of sub-surface water,although his explanations of the mechanics involved were not very scientific.His theory,now firmly established,is termed the infiltration theory,and states that underground water is the result of water seeping downwards from the surface,either directly from precipitation or indirectly from streams and lakes.This form of water is termed meteoric.A very small proportion of the total volume of sub-surface water is derived from other sources. Connate water is that which is trapped in sedimentary beds during their time of formation. Juvenile water is water added to the crust by diastrophic causes at a considerable depth,an example being volcanic water.During precipitation water infiltrates into the ground,under the influence of gravity,this water travels downwards through the minute pore spaces between the soil particles until it reaches a layer of impervious bedrock,through which it cannot penetrate.The excess moisture draining downwards then fills up all the pore spaces between the soil particles,displacing the soil air.During times of excessive rainfall such saturated soil may be found throughout the soil profile,while during period of drought it may be non-existent.Normally the upper limit ofsaturated soil,termed the water table,is a meter or so below the surface,the height depending on soil characteristics and rainfall supply.According to the degree of water-occupied pore space,sub-surface moisture is divided into two zones:the zone of aeration and zone of saturation,as illustrated in Fig4.1.This area extends from the surface down to the upper level of saturation-the water table. With respect to the occurrence and the circulation of the water contained in it,this zone can be further divided into three belts:the soil water belt,the intermediate belt and the capillary fringe (Fig.4.1)Assuming that the soil is dry,initial rainfall allows water to infiltrate,the amount of infiltration depending on the soil structure.Soils composed mainly of large particles,with large pore spaces between each particle,normally experience a more rapid rate of infiltration than do soils composed of minute particles.No matter what the soil is composed of some water is held on the soil particles as a surface film by molecular attraction,resisting gravitational movement downwards.The water held in this manner is referred to as hygroscopic water.Even though it is not affected by gravity,it can be evaporated,though not normally taken up by plants.This belt occurs during dry periods when the water table is at considerable depth below the surface.It is similar to the soil water belt in that the water is held on the soil particles by molecular attraction,but differs in that the films of moisture are not available for transpiration or for evaporation back to the atmosphere.In humid areas,with a fairly reliable rainfall,this belt may be non-existent or very shallow.Through it,gravitational or vadose water drips downwards to the zone of saturation.Immediately above the water table is a very shallow zone of water which has been drawn upwards from the ground-water reservoir below by capillary force.The depth of this zone depends entirely on soil texture,soils with minute pore spaces being able to attract more water from below than soils with large pore spaces.In the latter types of soil the molecular forces are not able to span the gaps between soil particles.Thus,sandy soils seldom exhibit an extensive capillary fringe,merging from soil water through to the zone of saturation.The zone of saturation is the area of soil and rock whose pore spaces are completely filled with water,and which is entirely devoid of soil air.This zone is technically termed ground water even though the term broadly includes water in the zone of aeration.The upper limit of the zone of saturation is the water table or phreatic surface.It is difficult to know how deep the ground-water zone extends.Although most ground water is found in the upper3km of the crust, pore spaces capable of water retention extend to a depth of16km.this appears to be the upper limit of the zone of rock flowage where pressures are so great that they close any interstitialspaces.The upper level of the saturated zone can be completely plotted by digging wells at various places.Studies suggest two quite interesting points(Fig.4.2).1)The water table level is highest under the highest parts of the surface,and lowest under the lowest parts of the surface.Hills and mountains have a higher level phreatic surface than valleys and lakes.The reason for this is that water continually percolating through the zone of aeration lifts the water table,while seepage from the ground-water zone into creeks and lakes lowers the level.2)The depth of the water table below the land surface is greatest in upland areas where the water moves quite freely downhill under gravity.Close to streams,lakes and swamps the water table is close to,if not at the surface,as water from the higher areas builds it up.What causes flooding?The basic cause is excessive runoff from catchment s into river systems incapable of carrying this extra volume.Can science and technology prevent flooding or,at least,reduce its severity?Unfortunately,this is a complex problem to which as yet there is no very satisfactory solution.Let us consider first the reduction of runoff from catchment areas.Some regions have soils which have low absorbing capacity.In a heavy rainstorm such soil is quickly saturated and all additional rainfall then runs off into the river.A seasonal variable is the moisture status of the soil at the commencement of a rainstorm.If the soil is already moist,a relatively minor storm could still cause heavy runoff because the soil is incapable of retaining additional moisture. These factors are not easily influenced by man.However,man’s utilization of the catchment area can have an important influence on rge scale cleaning of trees and scrub greatly reduces the capacity of the soil to retain water.It also tends to cause soil erosion which aggravates flooding by chocking rivers and streams with deposited silt.Correct management of catchment areas is therefore one important approach to the problem of flood control.More direct approach which is used in an emergency is the construction of levee s.when rising floodwaters threaten a township the citizens form work-parties to build barricade s of sandbags along the river bank,hoping that those barricades will hold back the flood waters until the emergency passes.It may be wandered why levees are not usually built as permanent structures to which the town is protected at all times.The reason is that levees are an unsatisfactory solution to the problem.If a levees collapses,the floodwaters escape as a sudden deluge with increased capacity for destruction.Levees as they divert the floodwater from one area frequently create or aggravate problems in another.They can be a cause of enmity between communities for this reason.Anther approach is the construction of dams so that floodwaters can be retained in a reservoir until the crisis is over,slow release of the water during the succeeding weeks or months would then be bined purpose irrigation and flood control dams would seem to be a logical solution.Unfortunately,a reservoir which is to be used for irrigation needs to be kept nearly full in winter,while one which is to be used for flood control needs to be kept empty,so that it is available as a water store when needed.This conflict of operating requirements means that combined purpose dams are rarely feasible.Separate dams would be required for flood control and their very high cost makes this an impractical solution.The next approach to the problem is that of improving the capacity of the river to carry larger volumes of water without overflowing its banks.A number of measures are available,some simple,some complex.They all have widespread effects on the river so any of these measures should be used as part of a comprehensive plan.Work of this kind is known as“river improvement”or“river management”.One simple,but important step is to ensure that the water course of a river is kept free of obstruction s.These frequently consist of dead trees which have fallen into the river,where they remain to impede the flow of water.They are called“snags”and the removal work“snagging”. Many of the trees that line Australian River banks are hardwoods,which are too heavy to float so they remain where they fall.Furthermore,hardwoods are very durable;large red gum logs have been known to survive over a hundred years under water.Another method of increasing the capacity of the river is to remove choking plant growth. Early settlers introduced willow trees to many of our river banks,partly for shade,partly to recall old England and hopefully to reduce the erosion of the river banks.Unfortunately,these trees are difficult to control and willow infestation is now quite commonly a problem. Protection of the banks of a river from erosion by the stream of water is another measure.Rivers which follow a meandering,or winding course tend to erode their banks along the outer curves. This can mean a loss of valuable soil from the eroded bank area and is also a cause of local flooding.Means of protecting banks from erosion have been devised.The simplest device used for this purpose is that of anchored or tied tree trunks along the eroded bank.The trunks protect the bank and encourage the deposition of silt on the bank so that it is gradually built up.Water,one of man’s most precious resources,is generally taken for granted until its use is threatened by reduced availability or quality.Water pollution is produced primarily by the activities of man,specifically his mismanagement of water resources.The pollutants are any chemical,physical,or biological substances that affect the natural condition of water or itsintended use.Because water pollution threatens the availability,quality and usefulness of water, it is of worldwide critical concern.The increase in the number and variety of uses for water throughout the world has produced a wide range of standards of water quality that must be satisfied.These demands include:①preservation of rivers in their natural state;②potability of the water supply;③preservation and enhancement of fish and wildlife;④safety for agricultural use;⑤safety for recreational use including swimming;⑥accommodation to a great variety of industrial purpose;⑦freedom from nuisance;⑧generation of power for public utilities;⑨dilution and transport of wastes.Besides the specific chemical,biological,and physical requirements for the multitude of uses noted above,there are constraints reflecting public health requirements, aesthetics,economics,and short and long-term ecological impacts.Consequently,there is no rigid or specific definition of water pollution,since the intended use or uses of the water must be taken into consideration in any definition of what constitutes polluted water.One method of classifying the gaseous,liquid and solid constituents of water that constitute pollution depends on the intended use of the water.The pollutants are then grouped as not permissible,as undesirable and objectionable,as permissible but not necessarily desirable, or as desirable.For example,if water is to be used immediately for animal consumption,toxic compounds are not desirable,whereas a certain amount of oxygen is not objectionable.On the other hand,if the water is to be used in a power plant for steam generation,toxic materials might be allowable or even perhaps desirable,whereas oxygen that could possibly corrode equipment would be objectionable.Another method of classifying pollutants that enter water as a result of man’s domestic, industrial or other activities is to distinguish between conservative and non-conservative pollutants.Conservative pollutants are those that are not altered by the biological processes occurring in natural waters.These pollutants are for the most part inorganic chemicals,which are diluted in receiving water but are not appreciably changed in total quantity.Industrial wastes contain numerous such pollutants,including metallic salts and other toxic,corrosive,colored, and taste-producing materials.Domestic pollution and return flow from irrigation may contain numerous such pollutants,including chlorides and nitrates.Non-conservative pollutants,on the other hand,are changed in form of reduced in quantity by chemical and physical processes involved in biological phenomena occurring in water.The most common source of non-conservative pollutants is domestic sewage－highly putrescible organic waste that can be converted into inorganic materials such as bicarbonates,sulfates,and phosphates by the bacteria and other microorganism in the water.If the water is not too heavily laden with wastes,it will undergo“self-purification”.This process involves the action of aerobic bacteria,that is,bacteria that require free oxygen to break down wastes,and it produces no offensive odors.If,however,the water is laden with wastes beyond a certain amount,the process of biological degradation becomes anaerobic.That is,it proceeds by the action of bacteria that do not require free oxygen.In the process,noxious hydrogen sulphide gas,methane,and other gases are produced.The aerobic and anaerobic processes that occur naturally in streams are used in sewage treatment plants and are,in fact,major elements in sewage treatment.The problem of water pollution has been and is almost worldwide.Planning can be defined as the orderly consideration of a project from the original statement of purpose through the evaluation of alternative s to the final decision on a course of action.It includes all the work associated with the design of a project except the detailed engineering of the structures.It is the basis for the decision to proceed with(or to abandon)a proposed project and is the most important aspect of the engineering for the project.Because each water-development project is unique in its physical and economic setting,it is impossible to describe a simple process that will inevitably lead to the best decision.There is no substitute for“engineering judgment”in the selection of the method of approach to project planning,but each individual step toward the final decision should be supported by quantitative analysis rather than estimates or judgment whenever possible.One often hears the phrase“river-basin planning”,but the planning phase is no less important in the case of the smallest project.The planning for an entire river basin involves a much more complex planning effort than the single project,but the difficulties in arriving at the correct decision may be just as great for the individual project.The term“planning”carries another connotation which is different from the meaning described above.This is the concept of the regional master plan which attempts to define the most desirable future growth pattern for an area.If the master plan is in reality the most desirable pattern of development,then future growth should be guided toward this pattern. Unfortunately,the concept of“most desirable”is subjective,and it is difficult to assure that any master plan meets this high standard when first developed.Subsequent changes in technology, economic development,and public attitude often make a master plan obsolete in a relatively short time.Any plan is based on assumptions regarding the future,and if these assumptions are not realized the plan must be revised.Plan generally must be revised periodically.An overall regional water-management plan,developed with care and closely coordinated with other regional plans,may be a useful tool in determining which of many possible actions。
水利水电专业毕业论文文献翻译中英文对照[管理资料]
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DamThe first dam for which there are reliable records was build or the Nile River sometime before 4000 . It was used to divert the Nile and provide a site for the ancient city of Memphis .The oldest dam still in use is the Almanza Dam in Spain, which was constructed in the sixteenth century. With the passage of time,materials and methods of construction have improved. Making possible the erection of such large dams as the Nurek Dam, which is being constructed in the . on the vaksh River near the border of Afghanistan. This dam will be 1017ft(333m) high, of earth and rock fill. The failure of a dam may cause serious loss of life and property; consequently, the design and maintenance of dams are commonly under government surveillance. In the United States over 30,000 dams are under the control of state authorities. The 1972 Federal Dams Safety Act (PL92-367)requires periodic inspections of dams by qualified experts. The failure of the Teton Dam in Idaho in June 1976 added to the concern for dam safety in the United States.1 Type of DamsDams are classified on the type and materials of construction, as gravity, arch, buttress ,and earth .The first three types are usually constructed of concrete. A gravity dam depends on its own weight for stability and it usually straight in plan although sometimes slightly curved.Arch dams transmit most of the horizontal thrust of the water behind them to the abutments by arch action and have thinner cross sections than comparable gravity dams. Arch dams can be used only in narrow canyons where the walls are capable of withstanding the thrust produced by the arch action. The simplest of the many types of buttress dams is the slab type, which consists of sloping flat slabs supported at intervals by buttresses. Earth dams are embankments of rock or earth with provision for controlling seepage by means of dam may be included in a single structure. Curved dams may combine both gravity and arch action to achieve stability. Long dams often have a concrete river section containing spillway and sluice gates and earth or rock-fill wing dams for the remainder of their length.The selection of the best type of dam for a given site is a problem in both engineering feasibility and cost. Feasibility is governed by topography, geology and climate. For example, because concrete spalls when subjected to alternate freezing and thawing, arch and buttress dams with thin concrete section are sometimes avoided in areas subject to extreme cold. The relative cost of the various types of dams depends mainly on the availability of construction materials near the site and the accessibility of transportation facilities. Dams are sometimes built in stages with the second or late stages constructed a decade or longer after the first stage.The height of a dam is defined as the difference in elevation between the roadway, or spillway crest, and the lowest part of the excavated foundation. However, figures quoted for heights of dams are often determined in other ways. Frequently the height is taken as the net height is taken as the net height above the old riverbed.on damsA dam must be relatively impervious to water and capable of resisting the forces acting on it. The most important of these forces are gravity (weight of dam) , hydrostatic pressure, uplift, ice pressure, and earthquake forces are transmitted to the foundation and abutments of the dam, which react against the dam with an equal and opposite force, the foundation reaction. The effect of hydrostatic forces caused by water flowing over the dam may require consideration in special cases.The weight of a dam is the product of its volume and the specific weight of the material. The line of action of dynamic force passes through the center of mass of the cross section. Hydrostatic force may act on both the upstream and downstream faces of the dam. The horizontal componentH of the hydrostatic force is the force or unit width of damhit is2/2HrhhWhere r is the specific weight of water and h is the depth of water .The line of action of this force is h/3 above the base of thedam .The vertical component of the hydrostatic force is equal to the weigh of water vertically above the face of the dam and passes through the center of gravity of this volume of water.Water under pressure inevitably finds its way between the dam And its foundation and creates uplift pressures. The magnitude of the uplift force depends on the character of the foundation and the construction methods. It is often assumed that the uplift pressure varies linearly from full hydrostatic pressure at the upstream face (heel)to full tail-water pressure at the downstream face (toe).For this assumption the uplift force U isU=r(h1+h2)t/2Where t is the base thickness of the dam and h1and h2 are the water depths at the heel and toe of the dam,respectively. The uplift force will act through the center of area of the pressure trapezoid.Actual measurements on dams indicate that the uplift force is much less than that given by Eq.(2)Various assumption have been made regarding the distribution of uplift of Reclamation sometimes assumes that the uplift pressure on gravity dams varies linearly from two-thirds of full uplift at the heel to zero at the toe. Drains are usually provided near the heel of the dam to permit the escape of seepage water and relieve uplift.译文：坝据可靠记载，世界上第一座坝是公元前4000年以前在尼罗河上修建的。
边坡的稳定性英语作文
边坡的稳定性英语作文英文回答：Slope stability is a critical aspect of geotechnical engineering, as it ensures the safety and stability of slopes in various construction projects. Several factors can affect slope stability, including the slope angle, soil properties, water content, and external forces such as earthquakes.To assess slope stability, engineers conduct detailed geotechnical investigations to analyze the soil conditions and identify potential failure mechanisms. Common methods include field investigations (e.g., soil sampling, boreholes) and laboratory testing (e.g., shear strength tests). These tests provide valuable data on soil parameters such as cohesion, friction angle, and permeability.Once the soil properties are determined, engineers canperform slope stability analysis using various methods, such as the limit equilibrium method or finite element analysis. These analyses help evaluate the factor of safety (FOS), which indicates the slope's resistance to failure compared to the destabilizing forces acting on it. A FOS greater than 1.5 is generally considered acceptable for most slopes.To enhance slope stability, engineers employ a range of techniques, including:Slope flattening: Reducing the slope angle increases the stability by decreasing the gravitational forces acting on the slope.Soil reinforcement: Installing geosynthetics or soil nails within the slope improves its shear strength and resistance to failure.Drainage systems: Installing drainage systems, such as perforated pipes or trenches, helps control water seepage and reduce pore water pressure within the slope.Retaining walls: Constructing retaining walls at the base of the slope provides lateral support and prevents the slope from collapsing.In summary, maintaining slope stability is crucial for ensuring the safety and integrity of slopes in construction projects. Through detailed geotechnical investigations, thorough analysis, and effective mitigation measures, engineers can design and implement slopes that can withstand various external forces and environmental conditions.中文回答：边坡稳定性是岩土工程的一项关键内容，它确保了边坡在各种建设项目中的安全和稳定。
外文翻译--水利水电工程施工
英文原文：Water Resources and Hydropower Engineering ConstructionDesign Layout[Key words] construction layout Fuzzy multiple attribute decisionmaking Water Resources and Hydropower Construction[Abstract] Analysis of affecting factors of the construction layout program characteristics that people value in identifying these indicators fuzzy constraints are difficult to give exact values, while decision-making process has been one of psychological, subjective will and the work experience and other aspects influence decision-making process and therefore there is certainly ambiguity.1, Water Resources and Hydropower Engineering Construction Layout FactorsConstruction advantages and disadvantages of the general layout scheme, involving many factors, from different angles to evaluate the evaluation factors generally have two categories, qualitative factors, and quantitative factors of a class. Qualitative factors are mainly: 1. Favorable production, easy to administer, facilitate the degree of life; 2. During the construction process, the degree of co-ordination; 3. The principal impact of construction and operation; 4. Meet the security, fire, flood prevention, environmental protection requirements; 5. Temporary Works and the combination of permanent works and so on. Indicators are mainly quantitative factors;1. Site preparation earthwork quantity and cost;2. The extent of use of earth excavation;3. Temporary works of construction work quantity and cost;4. Workload and a variety of materials, transport costs;5. Size and cost of land acquisition;6. Made to the area to field, the recovery or recycling construction fees.As the construction is construction planning layout content, is that people under work experience, combined with engineering data on the occurrence of a future prediction about. Therefore, both qualitative factors, and the quantitative factors, there is uncertainty. We know that the uncertainty of two different forms; one is uncertain whether the incident occurred in 11 random, the event itself the state of uncertainty 11 ambiguity. Randomness is an external cause in general uncertain, but ambiguity is an inherent uncertainty of the structure. From the information point of view, therandomness involves only the amount of information, while the ambiguity is related to the meaning of information. We can say that ambiguity is more profound than the randomness, the uncertainty more generally, especially in the subjective understanding of areas of role ambiguity is much more important than the role of randomness. Random people for a lot of research has been carried out, achieved fruitful results; while ambiguity was ongoing and in-depth knowledge and research in the. All people involved in the system, carried out by people planning, feasibility studies, evaluation of decision-making, design and management, and therefore, can not ignore the objective world of things in the human brain, one by one to reflect the uncertainty of ambiguity, it is an objective difference intermediate division caused by the transition of a kind of uncertainty. Construction Layout Design is no exception, in the arrangement of construction there are a large number of objective fuzzy factors. For example, the construction of facilities, coordination between the levels of "good" and "general" is an accurate value can not be described. Therefore, the arrangement can not ignore or avoid the construction of the fuzziness existing in the process, but should be objective and deal with ambiguity of this objective, understand the rules for people planning, demonstration, evaluation and decision, design and management to provide a scientific basis and methods.As the construction layout of the content involved in more programs fuzzy factors exist, the traditional construction arrangement he considered the existence of ambiguity, but in decision-making process has fuzzy information precision, not a real fuzzy optimization. Therefore, the program should focus on optimization of fuzzy factors into account, the ambiguity should be reflected in the decision-making on the index, index weights. For quantitative indicators, mainly the amount and cost of the project issues, its value can be found in engineering materials and design documents to determine by calculation, the results are the values of the parameters and experience. As every engineer's understanding of things is not the same experience in a certain range of parameter changes, the results also in a certain range. For qualitative indicators, according to experts, engineering experience, through expert scoring method, set the value of statistics to determine. Such subjective factors, the knowledge structure and decision-making preferences play a major role. But in practice, due to the complexity of objective things and the people's thinking on the use of fuzzy concept, to describe with precision the number becomes very difficult, but with "some", "left"and the like get fuzzy concept to describe the more reasonable. Determine the weights of evaluation indexes, there are many mathematical ways to determine the accurate calculation. We know, for different projects, in the same factors, their importance is not the same, then the mathematical model is difficult to fully reflect the actual situation, the help of experts in engineering experience must be judged.Since the existence of the above ambiguity, avoid or ignore the ambiguity is unscientific, incomplete. Previous index value that decision-making, decision weights for programs for determining the value of the preferred method, there is bound to sidedness and limitations. As technology develops, people are increasingly demanding of precision, the object of study become more complicated, as complicated to some degree after the meaning of the precise cognitive declines and the appropriate fuzzy but accurate. Here, the introduction of fuzzy mathematical tools, the use of modern fuzzy multiple attribute decision making theory, Fuzzy multiple attribute decision making model, can exist for people to consider the ambiguity of the objective, to provide strong support for rational decision-making.2, Water Resources and Hydropower Engineering Construction Design LayoutConstruction Layout as a focus of the system around the concrete layout of the temporary structures. There are 1. All kinds of storage, stockpile and Spoil; 2. Mechanical repair system; 3. Metal structure, mechanical and electrical equipment and construction equipment installed base; 4. Wind, water and electricity supply systems; 5. Other construction plant, such as steel processing, wood processing, prefabricated factory; 6. Office and living space, such as offices, laboratories, dormitories, hospitals, schools, etc.; 7. Fire safety facilities and other, such as fire stations, guard, and security cordon so. At this time, various types of temporary structures should be put forward, the construction of facilities furnished a list of partial pressure, their area, building area and volume of construction and installation; on fertilization with an estimate of land acquisition, land area and the proposed land use plan, the study to reclaiming land in the use of the measures, site preparation earthwork volume calculations, the integrated cut and fill balance of the proposed excavation of the use of effective planning.Construction of facilities in order to avoid conflict between the layouts, construction of facilities in the analysis of adjacency relations, is to analyze the relationship between the construction of facilities, strength of correlation andrelationship. Usually based on the adjacency relationship, consider the construction schedule, construction strength, facilities operation and logistics. Analysis of the size and layout of the construction of facilities present at the location of the ground between the site controlled the indicators are: 1. The scale of construction facilities layout, the main considerations to meet the construction requirements of the case, the construction of facilities, capacity and layout area. 2. Foundation bearing capacity of the construction of facilities to consider geology, slope stability and so on. 3. Hydrological requirements and construction guide closure of the case, consider the different construction periods, flood, water table, water level changes in the construction site layout planning of construction restrictions and impact. 4. The height difference logistics constraints, considering logistics and vertical elevation gradient lines, logistics of import and export. 5. Construction of the distance between these facilities and restrictions, mainly refers to the construction of facilities necessary for running the minimum operating radius, the minimum limit transportation question, minimum import and export logistics, construction and facilities, the safety distance between. 6. Construction site area of internal and external traffic conditions, construction equipment, consider the minimum safe height and width of the transport, building materials inside the transport requirements.To be concrete system facilities arranged in a prominent position, so that interference by the other facilities as small as possible, the need for construction of facilities at this time analysis of the relationship between the adjacent, as many facilities for Hydropower Construction, different facilities have a clear focus on functionality, such as depots, gas stations, etc., if not for the neighbor relations analysis, because the construction of facilities for the inter-functional conflict, construction and project management to bring incalculable damage and safety hazards buried.References:[1] Lu Yu Mei editor of the Three Gorges Dam Construction [M]. Beijing: China Electric Power Press, 2003[2] Wei-Jun Zhu, Zhang Xiaojun and so the overall layout design of the Three Gorges Project Construction [J]. The people of the Yangtze River, 2001.32 (10) :4-5.译文：水利水电工程施工的布置方案设计[关键词]施工布置模糊多属性决策水利水电施工[论文摘要]分析施工布置方案的影响因素特点，指出人们在确定这些指标值时受到模糊性因素的限制很难给出精确值，同时决策过程还受到人们心理、主观意愿和工作经验等多方面的影响，因而决策过程也必然存在模糊性。
公路边坡支护中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)公路边坡常见支护方法目前，我国山区高速公路建设迅猛发展。
在高等级公路的修建中，出现大量的深挖路堑与高填路堤边坡，其防护问题非常突出。
为了满足安全可靠和经济合理双重目标，对高边坡病害特征的深入分析和对其治理工程方案的慎重选择显得十分重要。
公路边坡沿公路分布的范围广，对自然环境的破坏范围大，如果在防护的同时，能够注意保护环境和创造环境，采用适当的绿化防护方法来进行，则会使公路具有安全、舒适、美观、与环境相协调等特点，也将会产生可观的经济效益、社会效益和生态效益。
边坡设计应遵循“安全绿色、水土保持、恢复自然、环保之路”的设计原则。
对公路边坡进行防护，必须考虑以下问题：①边坡稳定：保护路基边坡表面免受雨水冲刷，减缓温差与温度变化的影响，防止和延缓软岩土表面的风化、破碎、剥蚀演变过程，从而保护路基的整体稳定性。
②环境保护：使工程对环境的扰乱程度减少到最小，并谋求人工构造物与自然环境相协调。
③综合效应：综合防光，防眩，防烟，诱导司机视线，改善景观等目的进行边坡绿化防护，充分发挥防护工程的综合效益。
1、工程防护1.1 抹面与捶面1.1.1适用条件：①对各种易于风化的软岩层（如泥质砂岩、页岩、千枚岩、泥质板岩等）边坡，当岩层风化不甚严重时；②所防护的边坡，本身必须是稳定的，但其坡面形状、陡度及平顺性不受限制；③所防护的边坡，必须是干燥、无地下水的岩质边坡。
1.1.2构造要求：①抹面厚度一般为5～7cm，捶面厚度为10～15cm，一般为等厚截面。
②抹面与捶面工程的周边与未防护坡面衔接处，应严格封闭。
如在其边坡顶部做截水沟，沟底与沟边也要做抹面或捶面防护。
③大面积抹面或捶面时，每隔5～10m应设伸缩缝。
1.2 灌浆与勾缝灌浆适用于石质坚硬、不易风化、岩层内部节理发育，但裂缝宽度较小的岩质路堑边坡。
勾缝适用于石质较坚硬、不易风化、张开节理不甚发育，且节理缝较大较深的岩石路堑边坡上。
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水利水电工程专业外文翻译--边坡稳定性外文翻译1.1 IntroductionStability of SlopesGravitational and seepage forces tend to cause instability in natural slopes, in slopes of embankments and earth dams. The most important types of slope failure arc illustrated in Fig.1.1. In rotational slips the shape of the failure surface in section may be a circular are or a non-circular curve. In general, circular slips are associated with homogeneous soil conditions and non-circular slips with non- homogeneous conditions. Translational and compound slips occur where the form of failure surface is influenced by the presence of an adjacent stratum is at a relatively shallow depth bellow the surface of the slope: the failure surface tends to be plane and roughly parallel to the slope. Compound slips usually occur where the adjacent stratum is at greater depth, the failure surface consisting of curved and plane sections.Figure 1.1 Type of slope failureIn practice, limiting equilibrium methods are used in the analysis of slope stability. It is considered that failure is on the point of occurring along an assumed or a known failure surface. The shear strength required to maintain a condition of the limiting equilibrium is compared with theavailable shear strength of the soil, giving the average factor safety along the failure surface. The problem is considered in two dimensions, conditions of plane strain being assumed. It has been shown that two-dimensional analysis gives a conservative result for a failure on a three-dimensional (dish-shaped) surface. Figure 1. 2 The ?u=0 analysis1.2 Analysis for the Case of ?u=0The analysis, in term of total stress ,covers the case of a fully-saturated clay under undrained conditions, i.e. for the condition immediately after construction. Only moment equilibrium is considered in the analysis. In section, the potential failure surface is assumed to be a circle arc. A trial failure surface (centre O, radius and length La) is shown in Fig 1.2.Potentialinstability is due to the total weight of the soil mass(W per unit length) above the failure surface. For equilibrium the shear strength which must be mobilized along the failure surface is expressed as: ?m=?fCu= FFwhere F is the factor of safety with respect to shear strength. Equation moment1about O:CuLar FCuLar F= (1.1)Wd Wd=The moments of any additional forces must be taken into account. In the event of a tension crack developing, as shown in Fig1.2,the arc length La is shortened and a hydrostatic force will act normal to the crack if the crack fills with water. It is necessary to analyze the slope for a number of trial failure surfaces in order that the minimum factor of safety can be determined.Example 1.1A 45°slope i s excavated to a depth of 8m in a deep layer of unit weight 19kN/m3: the relevant shear strength parameters are cu=65kN/m3and ?u=0.Determine the factor of safety for the trial surface specified in Fig1.3. In Fig1.3, the cross-sectional area ABCD is 70m2. The weight of the soil mass=70×19=1330m2. The cent roid of ABCD is 4.5m from O.The angle AOC is 89.5°and radius OC is 12.1m.The arc length ABC is calculated as 18.9m. The factor of safety is given by:CuLar Wd65?18.9?12.165?18.9?12.1 =1330?4.51330?4.5 F==2.48This is the factor of safety for the trial failure surface selected and is notnecessarily the minimum factor of safety.Figure 1.3 example 1.11.3 The ?-Circle MethodThe analysis is in terms of total stress. A trial failure surface , acircular arc (centre o, radius r) is selected as shown in Fig 1.4.If the shearstrength parameters are cu and ?u ,the shear strength which must be mobilizedfor equilibrium is: ?m=?f=?l F =cm+?tan?mFigure 1.4 The ?-circle method2Where F is the factor of safety with respect to shear strength .Forconvenience the following notation is introduced: cm=cu (1.2) Fc tan?m=tan?u (1.3) F?it being a requirement that: FC=F?=FAn element ab, of length l, of the failure surface is considered, theelement being short enough to be approximated to a straight line. The forcesacting on ab (per unit dimension normal to the section) are as follows: (1)the total normal force ?1;(2) the component of shearing resistance cml;(3) the component of shearing resistance ?1tan?m.If each force cml along the failure surface is split into componentsperpendicular and parallel to the chord AB, the perpendicular components sumto zero and the sum of the parallel components is given by:C=cmLc (1.4)where Lc is the chord length AB. The force C is thus the resultant, actingparallel to the chord cml. The line of application of the resultant force Ccan be determined by taking moments about the centre O, then: C rc=r?cml i.e.cmLcrc=rcmLa where La=?l is the arc length AB. Thus,rc=Lar (1.5) LCThe resultant of the forces ?1and ?1tan?m on the element ab acts at angle ?m to the normal and is the force tangential to a circle, centre O, of radius r sin?m: this circle is referredto as the ?-circle. The same technique was used in Chapter 5.The overallresult (R) for the arc AB is assumed to be tangential to the ?-circle. Strictly, the resultant R is tangential to a circle of radius slightly greater than r sin?mbut the error involved in the above assumption is generally insignificant.The soil mass above the trial failure surface is in equilibrium under itstotal3weight (W) and the shear resultants C and R. The force W is known in magnitude and direction; the direction only of the resultant C is known.Initially a trial value of F? is selected and the corresponding value of ?m is calculated from equation 1.3.For equilibrium the line of application of the resultant R must be tangential to the ?-circle and pass though the point of intersection of the forces W and C. The force diagram can then be drawn, from which the value of C can be obtained .Then:cm =andFC=Cu CmC LCIt is necessary to repeat the analysis at least three times,starting with different values of F?.If the calculated values of FC areplotted against the corresponding values of F?,the factor of safetycorresponding to the requirement FC=F? can be determined .The whole procedure must be repeated for a series of trial failure surfaces in order that the minimum factor of safety is obtained.For an effective stress analysis the total weight W is combined with the resultant boundary water force on the failure mass and the effective stress parameters c′and ?′used.Based on the principle of geometric similarity, Taylor（1.13）published stability coefficients for the analysis of homogeneous slopes in terms of total stress. For a slope of height H the stability coefficients for the analysis of homogeneous slopes in terms of total stress. For a slope of height H the stability coefficient (Ns) for the failure surface along which thefactor of safety is a minimum is:Ns=Cu (1.6) F?HValues of Ns , which is a function of the slope angle ? and the shear strength parameter ?u,can be obtained from Fig 1.5.For ?u=0,the value of Ns also depends on the depthfactor D, where DH is the depth to a firm stratum. Firm stratumFigure 1.5 Taylor′s coefficients.In example 1.1, ?=45°, ?u=0,and assuming D is large, the value of Ns is 0.18.Then from equation 1.6:4F= =Cu Ns?H650.18?19?8 =2.37Gibson and Morgenstern〔1.4〕published stability coefficients for slopes in normally-consolidated clays in which the untrained strength cu(?u=0) varies linearly with depth.Figure 1.6 Example 1.2Example 1.2An embankment slope is detailed in Figure 1.6.Fir the given failure surface. Determine the factor of safety in terms of total stress using the ?-circle method. The appropriate shear strength parameters are cu=15kN/m2and ?u=15°: the unit weight of soil is 20 kN/m2.The area ABCD is 68 m2 and the centroid (G) is 0.60m from the vertical through D. The radius of the failure arc is 11.10m.The arc length AC is 19.15 m and the chord length AC is 16.85m. The weight of the soil mass is:W=68×20=1360 k N/m Th e position of the resultant C is given by:Lar LC19.15= ×11.1016.85r c=Now:?m=tan-1(tan15) F?Trial value of F? are chosen, the corresponding values of rsin ?m are calculated and the ?-circle drawn shown in Fig.1.6.The resultantC(for any value of F?) acts in a directions parallel to the chord AC and at distance rc from O. The resultant C(for any value F?) acts in a direction parallel to the chord AC and at distance rc from O. The forces C and W intersect at point E. The resultant R, corresponding to each value of F?, passes through E is tangential to the appropriate ?-circle. The force diagrams are drawn and the values of C determined.5感谢您的阅读，祝您生活愉快。