双安全系数动态局部强度折减法在边坡稳定分析中的应用

Application of Double Safety Factors and Dynamic Local Area Strength Reduction Method in Slope Stability Analysis

针对传统的强度折减法未考虑到边坡破坏过程中粘聚力和内摩擦角衰减速度的差异及边坡所有单元的强度参数均折减的问题,对边坡材料强度参数粘聚力和内摩擦角分别采用不同的折减系数,并根据屈服接近度判别标准,逐步调整折减区域,提出了边坡稳定分析的双安全系数动态局部强度折减法。实例应用结果表明,该方法能够较好地反映边坡破坏过程中粘聚力和内摩擦角衰减速度的差别,可模拟边坡失稳演变过程,得到的安全系数一般小于传统强度折减法和动态局部强度折减法。

Strength reduction method is widely used in slope stability and safety analysis, but this method has limitations： first, the different decay rates of cohesion and frication are not considered in typical strength reduction method; meanwhile, this method reduces the shear strength parameters of all elements of the slope. Thus, double safety factors and dynamic local area strength reduction method were put forward to remedy the defects of traditional strength method. In the new method, different reduction factors for cohesion and frication were adopted, and reduction area were gradually changed according to yielding approach index. The practical results show that the proposed method perfectly reflected the different decay rates of cohesion and frication and stimulated progressive failure of slopes, the safety factor is smaller than that of traditional strength reduction and dynamic local area strength reduction method.