基于颗粒流方法的典型下蜀土边坡滑动过程分析

Analysis of Sliding Process of Typical Xiashu Loess Slope Based on PFC Method

基于颗粒流方法,采用双轴模拟试验对下蜀土颗粒流模型细观参数进行标定,并利用细观参数对位于南京市挹江门街道旅游学校西侧山体的下蜀土滑坡进行数值模拟,研究滑坡变形破坏及滑动全过程。结果表明,滑坡最先在剪出口处发生变形,随后坡顶出现拉张裂隙并持续扩张,最终形成圆弧形滑面,为小型高速牵引式滑坡,滑坡土体停止滑动并最终在坡脚附近发生堆积。滑坡模型模拟的最终形态与实际滑坡形态相似,模拟滑距与实际滑距基本一致,结果较为可靠,可以对宁镇地区下蜀土滑坡破坏过程分析、划分致灾范围及工程治理提供依据。

Based on the method of Particle Flow,the micro-mechanical parameters of the granular flow model of the Xiashu loess were calibrated and obtained by biaxial simulation test.The calibrated micro-mechanical parameters was applied to numerical simulation of Xiashu loess sliding and the whole sliding process and deformation damage was studied.The results show that the landslide deformed first.With the appearance and of tensile cracks,the cracks continuously expanded and eventually composed a circular-arc sliding surface.Finally,the landslide stopped sliding and accumulated near the foot of the slope which formed a minor high-speed traction landslide.It was reliable that the final form of landslide model was similar to the actual landslide shape simultaneously.The numerical simulation sliding distance was basically identical to the actual sliding distance too.According to the simulation results,it could provide theory basis for analysis of landslide damage process,division of disaster area and slope management of the Xiashu loess slope in Nanjing and Zhenjiang area.