基于颗粒流方法的黄土地震滑坡数值模拟

基于颗粒流理论研究土质边坡动力稳定性及其滑动过程是近年来滑坡研究的一个新热点。在野外调查和室内试验的基础上，通过标定土体细观参数、模型建立、动力输入、动态监测等过程，利用PFC2D程序模拟了西吉县兴平乡堡湾村下马达子滑坡的失稳破坏运动过程，得到了该滑坡的破坏运动机理。得到如下结论:① 下马达子滑坡的失稳机制是在地震作用下斜坡前缘牵引、后缘推挤，使得坡肩受拉发生破坏，失稳后坡肩位置较大的速度和位移是地震滑坡破坏力强、致灾范围大的主要原因；② 黄土地震滑坡的滑坡后壁相对平缓，这是区别于重力滑坡的重要特征之一；③ 颗粒流模拟得到的滑坡前后相对高差和长度与实际情况较为吻合，因此，颗粒流方法可以用于地震滑坡滑距的预测。 

Numerical simulation of earthquake-induced loess landslides based on particle flow method

Research on the dynamic stability and sliding process of soil slopes based on particle flow theory is a new hot spot in landslide research in recent years. On the basis of field investigation and indoor experiment, the PFC2D program was used to simulate the instability failure movement process of the Xiamadazi landslide in Baowan village, Xingping township, Xiji county through the process of calibrating soil parameters, model establishment, power input, dynamic monitoring, etc., and the failure movement mechanism of the landslide is obtained. The following conclusions are obtained: ① The instability mechanism of the Xiamadazi landslide is that under the action of the earthquake, the leading edge of the slope is pulled and the trailing edge is pushed, causing the shoulder to be pulled and damaged. The larger velocity and displacement at the shoulder position after the instability is the main reason for the strong destructive force and the large disaster range of the earthquake landslide; ② The back wall of the earthquake-induced loess landslides is relatively flat, which is one of the important characteristics different from gravity landslides; ③ The relative altitude difference and length before and after the landslide obtained by particle flow simulation is more consistent with the actual situation. Therefore, the particle flow method can be used to predict the slip distance of earthquake landslides.