地震作用下黄土斜坡失稳及运动过程的离散元模拟  

DISCRETE ELEMENT SIMULATION OF INSTABILITY AND MOVEMENT PROCESS OF LOESS SLOPE UNDER SEISMIC LOADS

作　　者：王颖[1] 庄建琦[1,2] 李威 赵勇 贾艳军 WANG Ying;ZHUANG Jianqi;LI Wei;ZHAO Yong;JIA Yanjun(School of Geological Engineering and Geomatics,Chang an University,Xi’an 710054;Key Laboratory of Western China s Mineral Resources and Geological Engineering,Xi’an 710054)

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]长安大学西部矿产资源与地质工程教育部重点实验室,西安710054

出　　处：《工程地质学报》2018年第5期1139-1154,共16页Journal of Engineering Geology

基　　金：国家自然科学基金项目(41572272;41790444;41661134015)资助

摘　　要：在山区,地震诱发滑坡造成的人员伤亡往往占到地震总伤亡人数的一半以上,尤其是在黄土地区,由于地震造成的黄土滑坡具有运动距离远等特征,其灾难性更严重。针对地震诱发黄土斜坡的失稳峰值加速度、临界位移和运动距离等问题,本文利用离散元(PFC)方法,通过对室内三轴实验的应力-应变曲线进行标定和高精度航拍三维地形数据进行转化,以宁夏海口村黄土斜坡为研究对象,开展三维地震作用下斜坡失稳破坏和运动过程的数值模拟研究。通过监测不同位置在地震作用下的应力分量,计算监测点的p、q值并与室内三轴实验所得到p-q破坏线进行比较,获得斜坡破坏过程中的应力路径。结合颗粒的监测位移,获得斜坡失稳破坏的临界位移,得出该黄土斜坡失稳峰值加速度为0.135 g,临界位移为50 cm。同时根据不同地面环境条件,预测了在不同摩擦系数下斜坡失稳后的危害范围,为黄土地区边坡工程的抗震设计及防震减灾工作提供一种新的可视化方法。In mountainous areas,casualties caused by earthquake-induced landslides often account for more than half of the total earthquakes.Especially in the loess area,due to the far-distance loess landslide caused by the earthquake,the disastrousness is even more serious.This paper attempts to solve the problems of earthquake-induced loess slope instability such as peak acceleration,critical displacement and moving distance.It uses discrete element(PFC)method,calibrates the stress-strain curve of the indoor three-axis experiment,and transforms high-precision aerial three-dimensional topographic data.It takes the loess slope in Haikou Village,Ningxia Province as the research object to carry out numerical simulation of slope unstable failure and movement process under the three-dimensional earthquake.It monitors the stress components at different locations under the earthquake,compares the p and q values of the monitoring points with the p-q failure lines obtained from the indoor three-axis experiments.It obtains the stress paths and peak accelerations in the process of slope failure.Combining with the maximum displacement of the monitored particles,the critical maximum displacement of slope failure is obtained.The peak acceleration of the slope failure is 0.135g and the critical displacement is 50￣￣cm.At the same time,according to different ground environmental conditions,the damage range of the slope after sliding failure under different friction coefficients is predicted.The paper provides a new visualization method for the seismic design and earthquake prevention and mitigation of slope engineering in the loess area.

关 键 词：地震滑坡 离散元模拟 室内三轴实验 峰值加速度 临界位移 可视化 

分 类 号：P642.22[天文地球—工程地质学]