中文摘要：

在边坡失稳破坏过程中,黏聚力c和摩擦角Φ所起的作用是不相同的,边坡双安全系数虽然体现了c和Φ安全储备的不同,但其强度参数折减过程具有盲目性,并且在衡量边坡稳定性方面缺乏统一的标准。根据MohrCoulomb屈服准则,基于强度储备原理,提出综合安全系数;对土的软化过程进行推导,得到c和Φ折减系数之间的关系;利用FLAC3D中的fish语言编写自定义非等比强度折减程序,分析了不同强度参数折减比下边坡的稳定性。研究表明：1提出的综合安全系数消除了双安全系数在评价边坡稳定性方面的不确定性;2在黏土边坡失稳破坏过程中,黏聚力c所起的作用大于摩擦角Φ;3改进的强度折减法克服了传统强度折减法无法考虑滑动面土体劣化过程等问题。

英文摘要：

The shear strength parameters c,Φhave different exerting extent during the slope failure. Although the two safety factors fairly represent the differences of the strength reserve of c and Φ,its strength reduction are uncertainty,and there lacks a unified standard regarding to the measuring of the slope stability. In this paper,according to the Mohr-Coulomb yield criterion and the strength reserve principle,comprehensive safety factor was put forward; The relationship between reduction factors of c and Φwas obtained from the derivation of soil softening process; A user-defined program which expresses a nonproportional strength reduction method was compiled with the fish language in the FLAC3 Dto analyze slope stability based on different strength parameters. The main research results are as follows： 1Comprehensive safety factor eliminate the uncertainty of two safety factors in slope stability evaluation. 2The cohesion c plays a more important role than the internal friction angle Φ does in the clay slope destroy. 3The improved strength reduction method takes a consideration on the soil deterioration process that the traditional strength reduction did not do.