芒来露天煤矿北帮边坡滑坡机理分析

Analysis of landslide mechanism of north slope in Manglai Open-pit Coal Mine

为探究芒来露天煤矿北帮滑坡的成因和失稳机理,研究了滑坡区的地质概况、岩性特征和水文条件状况,采用FLAC3D模拟了滑坡过程与破坏特性,对边坡塑性区发展情况和滑坡渐进式破坏过程进行了详细分析,并采用强度折减法进行了稳定系数计算,揭示了滑坡主要原因和变形破坏机理。结果表明:多次滑坡位于同一位置,说明原始滑带上的岩土频繁被激活,造成滑坡;断层破碎带、软弱岩层及持续降雨是此次滑坡的关键因素;滑体受断层影响呈现明显以断层带为界限的滑动面,滑体从+910 m平盘的泥岩底板剪出,在滑体的中前段为剪切破坏,后端为拉张破坏,其破坏类型为牵引式滑坡整体变形破坏。

In order to explore the causes and instability mechanism of the north slope landslide in Manglai Open-pit Coal Mine,the article studies geological situation,lithologic characteristics and hydrological conditions of the landslide area,simulates the landslide process and failure characteristics by FLAC3D,analyzes the development of slope plastic area and progressive failure process of landslide in detail,and calculates the stability coefficient by strength reduction method,reveals the main causes and deformation failure mechanism of landslide.The results show that multiple landslides are located in the same position,indicating that the rock and soil on the original sliding zone are frequently activated,resulting in landslides;fault fracture zone,weak rock stratum and continuous rainfall are the key factors of the landslide.Affected by the fault,the sliding mass presents a sliding surface obviously bounded by the fault zone.The sliding mass is cut out from the mudstone floor of+910 flat plate.The middle and front section of the sliding mass is shear failure and the rear end is tension failure.The failure type is traction landslide overall deformation failure.