基于GTS的地震作用下三官庙滑坡稳定性研究

Study on the Stability of San'guanmiao Landslides under Earthquake Based on GTS

辽阳市弓长岭区三官庙滑坡体处在Ⅶ度地震烈度区,滑坡体呈对滑状,滑坡体整体坡度较缓,受渠内污水的润滑作用,该滑坡目前处于蠕动变形阶段。采用Midas-GTS建立有限元仿真动态模拟分析模型,对三官庙滑坡在天然工况和地震工况下的稳定性进行了分析。考虑未来50 a地震超越概率10%工况,采用峰值为0.1g的时程荷载,运用四边形循环化网格法进行网格拓扑,对岩土体物理参数进行强度折减,分析坡体剪切应变区及等效塑性区,确定潜在滑动带,并将其与极限平衡法所得结果进行对比分析,两者拟合度很好,计算结果显示斜坡在天然状态下基本稳定或稳定,安全系数为1.2~1.3,但由于峰值为0.1g的地震动加速度的加入,安全系数降至为1或以下,边坡处于不稳定状态。

The landslide of San＇guanmiao in Gongchangling District of Liaoyang city lies in the zone of Ⅶ degree earthquake intensity,and slides on both sides. Although the slope of the landslide is gentle,with the lubricating effect of the polluted water within the sewage canal,the landslide is currently in the creep deformation stage. The finite element simulation model was established by Midas-GTS to calculate and stability of Sanguanmiao landslide under the condition of natural condition and seismic condition. Considering the seismic probability exceeding by 10 % in 50 years,the grid topology is made by adopting the quadrilateral circular grid method with the peak of time history load 0. 1 g to make the strength reduction on the physical parameters of rock mass. Through analyzing the slope shear strain and equivalent analysis of plastic zone,the potential sliding zone is determined. Compared with the result by limit equilibrium method,it is found that both fit very well. The calculating results show that the slope basically keeps stable in the natural state,with the safety coefficient varying from 1. 2 to 1. 3. But with the participation of the acceleration of 0. 1 g for dynamic peak of earthquake,the slope become in an unstable state with the safety coefficient of 1 or lower.