地震动荷载下黄土滑坡离散元模拟

Discrete Element Simulation of Loess Landslide Under Earthquake Loads

为了深入探究地震荷载作用下黄土滑坡的运动滑移规律,采用离散单元法对甘肃黑方台滑坡进行不同地震荷载作用下的滑坡体运动数值模拟研究.结果表明,地震荷载作用下的黄土滑坡存在滑源区、流通区以及堆积区三个部分,滑源区的残积土结构相较于滑动前更加松散,滑源区近坡面不同位置颗粒的滑动位移差异性较大,处于滑坡体前缘的颗粒位移量最大,处于滑坡体后缘以及滑坡体最前缘的颗粒位移量较小;随着深度的增加,颗粒的位移量逐渐减小,且差异性较大;在不同地震动荷载作用下,滑源区颗粒的位移和速度变化差异性不大,但是较大的地震荷载会对深层颗粒的速度和位移产生影响,产生较大影响的时间刚好处于地震荷载的峰值时间;滑坡体滑距随着地震荷载的增加而线性增加.研究成果可为黄土地区地震滑坡的防治和规划提供一定的理论参考.

In order to deeply explore the motion and slip laws of the loess landslide under earthquake loads,the discrete element method is used to study the numerical simulation of the landslide mass motion of the Heifangtai landslide in Gansu under different earthquake loads.The results show that the loess landslide under seismic load has three parts:the source area,the circulation area and the accumulation area.The residual soil structure in the sliding source area is looser than that before the sliding.The sliding displacement of the particles at different positions near the slope surface in the sliding source area is quite different.To be exact,the displacement of the particles at the leading edge of the landslide is the largest,and the displacement of the particles at the trailing edge of the landslide and the leading edge of the landslide are smaller.With the increase of the depth,the displacement of the particles gradually decreases,and the difference is large.Under the action of different seismic loads,the displacement and velocity changes of the particles in the sliding source area are not very different,but the larger earthquake loads will have an impact on the velocity and displacement of the deeper particles,and the time which exerts a greater impact is just right the time at the peak of the seismic load.The slip distance of the landslide increases linearly with the increase of the seismic load.The research results can provide some theoretical reference for the prevention and planning of earthquake landslides in the loess area.