基于强度折减的岩质开挖边坡加固效果三维分析

Three-dimensional analysis on reinforcement effect of excavated rocky slope based on strength reduction technique

结合盐津变电所岩质开挖边坡实例,将稳定性分析的强度折减法与边坡的开挖、加固过程模拟相结合,对三维条件下边坡开挖和加固后的稳定性进行了计算评价。计算中应用了FLAC3D软件。研究表明,基于强度折减法的数值计算可以像数值模拟方法那样既考虑三维效应明显的地形地貌、地质结构和加固方式等,又考虑岩土体的本构关系和支挡结构与坡体的相互作用,还可以像极限平衡法那样计算安全系数,却不用指定滑面。同时采用强度折减法计算安全系数时,还能够考虑开挖、回填及加固等施工效应。计算结果还表明,在计算中应根据岩土体的应力应变关系、边坡的变形情况及工程的使用期限等恰当的选择岩土体抗剪强度参数,其结果将直接影响到强度折减法计算安全系数的精度。

The strength reduction technique for stability analysis is combined with the numerical simulation of excavation process and reinforcement measures to evaluate the effectiveness of reinforcement for the rocky slope in a substation project. The software FLAC3D is used for computation. The result shows that the numerical calculation based on strength reduction technique can not only consider the geomorphy, geologic structure and reinforce measure but also the constitutive relationship of rock and the interaction between structure and Slope. At the same time the effect of excavation, filling and reinforcement are also taken into account. It is also found that the determination of shear strength parameters should be according to the stress strain behavior, deformation and requirement of the project since it will directly affect the accuracy of the safety factor obtained from strength reduction technique.