基于位移突变准则的颗粒流强度折减法

采用颗粒流强度折减法评价边坡稳定性的关键是临界破坏状态的判定。以某边坡工程为例,利用PFC~(2D)程序对土体进行双轴压缩试验,标定了土体的细观参数并建立边坡颗粒流模型。对位移突变准则进行改进,通过绘制特征颗粒位移与折减系数关系曲线求解边坡稳定系数,并研究特征颗粒的选取方式。研究结果可重现边坡滑动破坏的形态变化,模拟的边坡破坏形态与有限元强度折减法和Bishop法结果一致,研究结果可为颗粒流强度折减法求解边坡稳定系数及滑坡模拟提供参考和借鉴。

Particle Flow Strength Reduction Method Based on Displacement Mutation Criterion

The key to using the particle flow strength reduction to evaluate the slope stability is the judgment of the critical failure state. Tooking a slope project as an example, the PFC2D code was used to simulate a biaxial compression test on the soil to calibrate its mircroscopic parameters. A particle flow model of the slope was established. Then, the criterion of displacement mutation was improved. The stability factor of the slope was solved by drawing the relation curve between characteristic particles and reduction coefficients. Besides, the selection of the characteristic particles was studied. The method in this paper can reproduce the morphological changes of slope sliding failure. The simulated failure mode of slope is consistent with the finite element strength reduction method and the Bishop method. The research results can provide references for the particle flow strength reduction to solve the stability factor of slope and the simulation of landslides.