强度折减法作为目前计算边坡安全系数常用方法之一，一直应用于边坡稳定设计研究。首先介绍了强度折减法的基本原理、计算步骤，利用 FLAC3D 内置语言 FISH 编制了相应计算控制程序，使强度折减法在 FLAC3D 程序中得以实现；接着，建立了不同因素水平下的边坡数值模型，采用强度折减法计算了各工况下边坡稳定的安全系数；最后，采用灰色关联度理论分析了安全系数与各影响因素的变化规律。分析结果表明：简单均质边坡稳定各影响因素之中，初始应力场为最重要的影响因素，强度参数及泊松比的影响大于边坡几何参数的影响，变形模量因素影响最小。

The strength reduction method is used widely in design of slope stability as a common method for calculating safety factor. This paper introduces the basic principle and computational procedure of the strength reduction method ； programs the calculation program in FISH language built in FLAC3D ； establishes numerical slope models under different factors and levels ； and calculates out the safety factors of slope stability under different working conditions using the strength reduction method. Finally, the relationship between safety factor and impact factors is obtained using grey correlation analysis. The results indicate that the initial stress field is the maximum one of all impact factors on simple isotropic slope, the intensity parameters and Poisson ratio have a bigger impact than geometric parameters, and the deformation modulus are the smallest.