基于离散元循环荷载作用下的边坡稳定性分析  

Slope Stability Analysis Based on Discrete Element Cyclic Loading Effect

作　　者：朱厚影 李学丰 ZHU Houying;LI Xuefeng(School of Physics and Electrical-Electronic Engineering,Ningxia University,Yinchuan 750021,China;Solid Mechanics Institute,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学物理与电子电气工程学院,宁夏银川750021 [2]宁夏大学固体力学研究所,宁夏银川750021

出　　处：《宁夏工程技术》2023年第1期12-17,共6页Ningxia Engineering Technology

基　　金：国家自然科学基金项目(1216020092);宁夏科技创新领军人才计划项目(KJT2019001)。

摘　　要：以宁夏贺兰山东麓沿线分布的碎石土竖直边坡为研究对象,运用PFC 2D软件建立二维模型,分析动力荷载作用下的边坡稳定性,并根据颗粒位移及应力演变过程中的监测数据,分析碎石土边坡的滑动与灾变演化特征。结果表明:在2种动力荷载作用下,坡面颗粒最大运动距离均超过5 m;横向地震波作用时,颗粒在临空状态下产生的横向位移较大;纵向地震波作用时,颗粒沿坡面滚落;2种动力条件下坡体内的应力演变规律较为接近,应力变化与坡面的距离相关,距离越大,应力降低的速度越慢,幅度越小;纵向地震波作用时,其滑动范围小于横向地震波,但应力释放快于横向地震波;由坡体内部应力变化幅度可知,在动力荷载条件下,坡内大部分区域的应力降低至初始应力的1/10,不利于灾害防治。Taking the vertical gravel soil slope distributed along the eastern foot of Helan Mountains in Ningxia as the research object,a two-dimensional model was established by PFC 2D software to analyze the stability of the slope under dynamic load.Based on the monitoring data of particle displacement and stress evolution,the sliding and catastrophic evolution characteristics of gravel soil slope were analyzed.The results show that the maximum movement distance of slope particles is more than 5 m under two kinds of dynamic loads.When the transverse seismic wave acts,the transverse displacement of the particles in the free state is larger,and when the longitudinal seismic wave acts,the particles roll down along the slope.The stress evolution law of the slope body under the two dynamic conditions is relatively close,and the stress change is related to the distance of the slope surface.The greater the distance,the slower the stress reduction rate and the smaller the amplitude.The sliding range of longitudinal seismic wave is smaller than that of transverse seismic wave,but its stress release is faster than that of transverse seismic wave.It can be seen from the variation range of the internal stress of the slope that the stress in most areas of the slope is reduced to 1/10 of the initial stress under the condition of dynamic load,which is not conducive to disaster prevention and control.

关 键 词：边坡稳定性 滑坡机制 颗粒流 离散元 

分 类 号：TU432[建筑科学—岩土工程]