边坡开挖诱发滑坡离散元模拟

Discrete element simulation of landslide induced by slope excavation

为直观反映滑坡从形成到变形、破坏的全过程,以边坡开挖诱发的大黄公路1号滑坡为例,在现场调查的基础上,结合室内试验结果,以预测其形成机制和致灾范围。采用离散元模拟技术,根据滑坡工程地质特征建立原始边坡模型,并对边坡开挖前、后2个阶段进行离散元模拟。通过对滑坡及跟踪点运动过程、速度和加速度变化的分析,判断该滑坡目前处于蠕滑滑动阶段、稳定性差。研究结果表明:大黄公路1号滑坡是由边坡开挖引起的以水平方向运动为主的牵引式滑坡;滑坡的运动过程可分为低速蠕滑、高速滑移、减速缓动和自稳调整4个阶段;滑坡若失稳,将对公路来往车辆、行人造成威胁,最大威胁距离达41.3m,公路上的滑坡堆积体可达2.5×104 m3,将严重影响公路的正常运行。

In order to reflect the whole process of the landslide from deformation to failure,this paper took No.1landslide on Dahuang highway which is introduced by slope excavation as an example to predict its formation mechanism and hazard range based on field investigation and laboratory test results.The discrete element numerical simulation method is used to simulate the previous and later stage of excavation slope model according to the landslide engineering geological characteristics.The analyses of movement,velocity and acceleration of the landslide and trace points in the model show that No.1landslide on Dahuang highway is currently in the stage of creep sliding with poor stability.The results show that No.1landslide on Dahuang highway is a retrogressive landslide in the horizontal direction,which is mainly induced by slope excavation.And the evolution process of landslide can be divided into the following four stages,low-speed creeping stage,high-speed moving stage,deceleration slow-moving stage and self-stabilizing stage.The results also reveal that the landslide will pose a threat to the vehicles and pedestrians on the highway,and the greatest threat distance is up to 41.3m.While the volume of landslideon the highway is up to 2.5×104 m3,it will seriously affect the normal operation of the highway.3tabs,11 figs,10refs.