一种考虑变形参数和强度参数协调折减的强度折减法研究

对于一种确定的岩体材料而言，岩体的变形参数与强度参数存在一种必然的内在联系。从材料性质来看，强度折减法的本质就是在当前边坡构型和岩体重度条件下，寻找另一种合适的岩体材料使边坡恰好达到临界状态。显然，若只对黏聚力和内摩擦角进行折减而其他参数保持不变，折减后的材料参数则可能违背岩体强度与变形参数之间存在的必然联系，即新找到的岩体材料客观上不存在。因此，在对黏聚力和内摩擦角进行折减时，有必要对岩体的其他力学参数进行调整。基于以上认识，提出了一种考虑变形与强度参数协调折减的强度折减法，探讨了变形参数（弹性模量和泊松比）、抗拉强度对安全系数、塑性区的影响，结果表明，同时考虑变形参数与强度参数协调折减的方案所得的安全系数最小，与极限平衡法的计算结果最为接近，且该方案所得的剪切塑性区主要集中在临空面附近，边坡模型中下部的剪切塑性区范围较小，同时，在边坡顶部区域出现张拉屈服区，此种塑性区分布范围最接近边坡实际破坏状态。

A strength reduction method considering reduction of strength parameters coordinating with deformation parameters

There is an inherent relationship between deformation and strength parameters for a typical rock mass. From the perspective of material properties, the essence of the strength reduction method (SRM) is to search another appropriate rock mass, which could lead to a slope at the critical state under the current slope conditions. It is obvious that when the cohesion and friction angle are reduced but other mechanical parameters remain unchanged, the new mechanical parameters may be contrary to the inherent relationship, and thus the newly found rock mass might not be exist objectively. Therefore, it is necessary to adjust the mechanical parameters of rock mass during the reduction of cohesion and internal friction angle. Based on the above analysis, we propose a strength reduction method which considers the deformation and strength parameters of the coordination fold reduction. Then, the deformation parameters (i.e., elastic modulus and Poisson's ratio), tensile strength of safety coefficient, plastic zone are discussed in detail. The results indicate that the safety factors obtained by the proposed method are very close to those calculated by the limit equilibrium method. In addition, the distribution of the plastic zones in the failure slope is in agreement with that of the real slope state. The plastic shear zones mainly appear near the free face of a slope, while the plastic tensile zones largely locate at the top of the slope.