【正文】 he 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 of applications ( pressure on retaining walls). However, analytical solutions have a special usefulness in engineering practice, particularly in terms of obtaining approximate solutions. More rigorous methods, . finite element technique, can then be used to pursue a detail solution. Bishop39。sI and39。s (1952) method were used to pare the overall factors of safety with respect to the slip surface determined by the proposed analytical method. Assuming k=0 for parison with the results obtained from the local minimum factorofsafety and Bishop39。The use of the slip circle in the stability analysis of slopes39。State of the art: limit equilibrium and niteelement analysis of slopes39。, Geotechnique, 15, 139}160 (1965). 14. B. M. Das. Principles of Geotechnical Engineering, PWS Publishing Company, Boston, 1994. 15. A. W. Skempton and H. Q. Golder. amp。he Art of Scienti,c Computing, Cambridge University Press, Cambridge, 1995. 20. M. G. Anderson and K. S. Richards. Slope Stability: Geotechnical Engineering and Geomorphology, Wiley, New York, 1987. 21. R. Baker. amp。Generalized three dimensional slope stability analysis39。 安全的因素所獲得的分析方法是符合最初 最低基本安全因素的方法 — 切割法。他的解決擋土墻土應力的方法用的是滑動面，在 1820 年法國這個被延伸用來分析邊坡。 這個方法的滑動到數(shù)片仍然在被使用 ,它形成了許多現(xiàn)代分析基礎 ,然而 ,大多數(shù)的這些方法的使用條款所有切片使計算邊坡穩(wěn)定性分析中所涉及的重復性和艱苦的過程。為解決邊坡穩(wěn)定性分析，陳和 Liu12 發(fā)表的解析在 ?? 坐標系里是利用變分微積分 ,和 ?? 對數(shù)螺旋線破裂面的來分析的。地震效應可以在位移模擬的分析方法中被更好的模擬是公認的。在沒有排水措施的前提下，剪切力 uc 很大程度上是和壓力無關的，也就是說 u? =，不管是密實的或者是有摩擦的，他們的系數(shù) 39。經(jīng)常采用直剪試驗或 CU測試孔隙 水壓力是因為測試時間是相對較短的。???圖 平面破壞 圖 1 顯示一典型的平面失敗的斜坡。振動力是接近包括同一水平線上的重力加速度，它產(chǎn)生了一個水平方向的作用在滑動體重心上的力 KW，并且不考慮豎直方向的慣性。公式（ 1）利用容重和水壓力界限可以來解決平衡問題，或者通過公式（ 2）利用浮容重和滲流壓力。( , )c? 都是遵循上述規(guī)律的。一個安全系數(shù)的解析表達式發(fā)展并且被應用了，這是不同于 Das 所提出的分析方法的。雖然利用 ?? 坐標系 來解決方案是一個綜合的測驗和有用的方法 ,但是這種方法是十分復雜的。大量的計算機技術已經(jīng)發(fā)展到自動化許多這樣的過程。 1916 年，不規(guī)則的破壞面在碼頭結構破壞中出現(xiàn)在瑞典。 關鍵詞 :解析方法 。Rapid evaluation of the critical surface in slope stability problems39。, Int. J. Numer. Anal. Meth. Geomech., 4, 333}359 (1980). 22. A. K. Chugh. amp。, Proc. 2nd Int. Conf. SMFE, Rotterdam, Vol. 2, 1948, pp. 63}70. 16. L. Bjerrum, and T. C. Kenney. amp。Determination of critical slope failure surface39。The early history of circular sliding surfaces39。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 m。0 3 1 3 2 3032 2 201sin sin sinc o t ( ) ( ) ( 2 ) ( 3 3 )1 2 2 2 3l l ls llI y y x d x y y x d x y y x d xH H b l Hl l l l l a b b H Hr r r?? ? ? ? ? ?? ? ? ? ? ? ? ? ?? ? ? (22) ? ? ? ? ? ?? ?? ?? ?? ?222222032310 30c4612c o ta r c s i n2t a na r c s i n21a r c s i n2c o t412c o sc o sc o s1100aHalablrrrHHarrarbraHbrHrrHldyydyydyyI xllxllxl????????????????? ??????????????? ?????? ??? ??? ????????? （ 23） 其中， ? ? 221 2 30 , ta n , ,y y x y H y b r x a?? ? ? ? ? ? ? （ 24） ? ? 220201c o t , c o t ,22l a H l a H l a r b H??? ? ? ? ? ? ? ? (25) It can be observed from equations (21)~(25) that the factor of safety Fs for a given slope is a function of the parameters a and b. Thus, the minimum value of Fs can be found using the Powell39。oe failure1s using 0()Hh? instead of H. For flatter slopes, failure is deepseated and extends to the hard stratum forming the base of the clay layer, which is called Base failure, as shown in Figure ,3 Following the same procedure as that for 185。39。39。 Sons, Ltd. Key words: analytical method。 dynamic effect。 and amp。 can be written as (c os s in )N W k???? （ 3） (si n c os )T W k???? （ 4） where is the inclination of the failure surface and w is given by 02( ta n ta n ) ( ta n )( c o t c o t )2LW x x d x H x d xH? ? ? ? ?? ??? ? ? ????? （ 5） where ? is the unit weight of soil, H the height of slope, c ot , c ot ,L H l H? ? ??? is the inclination of the slope. Since the length of the slide surface AB is /sincH ? , the resisting force produced by cohesion is cH/sin a. The friction force produced by N is (c os si n ) ta nWk? ? ?? . The total resisting or antisliding force is thus given by ( c os si n ) t a n / si nR W k c H? ? ? ?? ? ? （ 6） For stability, the downslope slide force 185。39。s method avoids a buildup of linear dependence. The closedform slope stability equation (21) allows the application of an optimization technique to locate the center of the sliding circle (a, b). The minimum factor of safety Fs min then obtained by substituting the values of these parameters into equations (22)~(25) and the results into equation (21), for a base failure problem (Figure 4). While using the Powell39。 the friction angle is 。 J. Soil Mech. Found, ASCE, 99(7), 495}507 (1973). 8. Y. Kohgo and T. Yamashita, amp。 Can. Geotech. J., 20(1), 104}119 (1988). 12. W. F. Chen and X. L. Liu. 184。Longterm stability of clay slopes,39。ondon, 36(1), 57}64 (1986). 23. B. M. Das. Principles of Soil Dynamics, PWSKent Publishing Company, Boston, 1993. 24. S. L. Huang and K. Yamasaki. amp。 地震 被認為是用 和振動 相似的方式產(chǎn)生的地震從屬效應。動力學因素 。到十九世紀五十年代中期，人們的注意力轉移到了用圓形和非圓形滑動面的分析上了。 承擔合理的滑動面是 斯潘塞 (1969)發(fā)現(xiàn)考慮的 圓形滑移面和對數(shù)螺旋滑動面是同樣臨界的使用目的。 在此研究中圓形滑動面是用于粘土質斜坡分析框架內(nèi)的一個 。39。39。在一些重要的二維滑坡的應用是可以應用的。安全因素 sF 可以由 R和 T的比例來確定，也就是： 1 ta n 2ta nta n ( s in c o s ) s in ( )