地震作用下岩石边坡稳定性有限元模拟

Rock slope stability under earthquake action with finite element analysis

为研究地震作用下岩石边坡的稳定性问题,根据实验室直剪实验结果确定了完整的岩石样本的抗剪指标参数,并根据岩体裂隙间距对其进行了弱化折减.采用有限元强度折减方法评估了含节理岩石边坡的稳定性,计算了临界滑移面的安全系数.通过Drucker-Prager破坏准则判断岩石边坡有限元模型中每个单元的滑移状态.采用准静态方法模拟岩石边坡地震作用荷载,讨论地震动力放大系数对边坡抗滑稳定性安全系数的影响.基于有限元分析结果,确定不同地震作用组合下岩石边坡在极限状态下的塑性区分布和滑移面的安全系数.

In order to study the stability of rock slope under earthquake action, the shear strength parameters of intact rock specimens are determined according to direct shear test in laboratory, and the equivalent shear strength parameters of jointed rock mass are modified by multiplying a reduced factor according to joint spacing in rock slope. Shear strength reduction approach is applied to evaluate stability of jointed rock slope and calculate safety factor of sliding surface based on finite element analysis. Drucker-Prager fracture criterion is used to evaluate the sliding state of every element of finite element model for rock slope. Jointed rock slope is simplified as homogeneous materials after modifying shear strength parameters. The earthquake actions are simulated by using quasi-static method. The influences of seismic dynamic magnification coefficient on safety factor of sliding surface are discussed. The distributions of plastic zone at collapse state and safety factor of sliding surface are determined according to computing results of finite element method.