基于土体软化规律的双折减系数法研究

Research on double reduction factors method based on soil softening law

双折减系数法(DRM)在边坡稳定性评估中正逐渐得到广泛应用,但是在计算过程中强度参数的折减规律以及2个折减系数之间的关系值得进一步探讨。基于边坡临界强度参数曲线和初始强度参数,以正切角的概念推导折减比例公式,分析其几何意义以及物理意义。依据算例结果,探讨折减比例与强度参数折减路径的关系。以土体材料强度参数遵循线性软化衰减规律,推导内摩擦角与黏聚力的函数关系式,将关系式引入经典强度折减法,提出一种基于土体软化规律的双折减系数法。算例表明,该方法在计算中充分考虑了岩土体材料本身强度参数衰减规律,计算过程更加符合实际情况。

In the analysis of slope stability,the double reduction factors method(DRM)is gradually widely used.However,in the process of calculating,the reduction law of strength parameters and the relationship between the two reduction factors deserve to be further determined.Firstly,based on the critical strength parameter curve and initial strength parameter of slope,the reduced proportion formula was deduced with the concept of tangent angle,and its geometric and physical meanings were analyzed.Then the relationship between the reduction ratio and the reduction path of strength parameters was analyzed based on the results of an example.Secondly,according to the linear softening attenuation law of soil material strength parameters,the functional relationship between internal friction angle and cohesion was deduced.The relationship was introduced into the classical strength reduction method,and a double reduction coefficient method based on the law of soil softening was proposed.Finally,the numerical result shows that the attenuation law of strength parameters of geotechnical materials is fully taken into account in the calculation,and the calculation process is more in line with the actual situation.