地下采空诱发陡倾层状岩质斜坡失稳机制研究  

FAILURE MECHANISM OF STEEPLY INCLINED ROCK SLOPES INDUCED BY UNDERGROUND MINING

作　　者：李滨[1] 王国章[2] 冯振[1] 王文沛[3] 

机构地区：[1]中国地质科学院地质力学研究所国土资源部新构造运动与地质灾害重点实验室,北京100081 [2]上海交通大学船舶海洋与建筑工程学院,上海200240 [3]中国地质环境监测院,北京100081

出　　处：《岩石力学与工程学报》2015年第6期1148-1161,共14页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(41472295;41302246);地质调查项目(1212011220140)

摘　　要：以重庆武隆鸡冠岭陡倾层状岩质斜坡滑动为例,采用FLAC3D模拟分析地下采空诱发陡倾层状岩质斜坡"弯曲变形→层间错动→采矿加速倾倒变形→下伏岩体阻滑→下伏岩体剪切破坏→整体失稳"的渐进失稳过程,认为鸡冠岭山体滑动是一类层状岩体的倾倒–滑移失稳的复合破坏模式。模拟结果表明:(1)陡倾临空的斜坡在长期重力作用下,坡体沿山梁方向发生蠕滑变形,坡体逐渐产生拉裂缝;同时由于该斜坡位于背斜核部附近,应力集中导致上覆层状岩体呈现出弯曲变形的特征;(2)长期岩溶作用加速坡体裂缝的发育与扩张;(3)斜坡下部煤层开采导致鸡冠岭山梁发生应力发生重分布,上覆层状岩体逐渐发生层面分离,层状岩体下部产生裂缝,岩体强度逐渐降低;(4)当斜坡下部煤层逐渐采空后,上覆层状岩体变形急剧增大,发生倾倒破坏,挤压矿层下伏稳定岩体,发生剪切滑移,最终从临空处剪出形成高速碎屑流。因此,对于西南灰岩褶皱山区,认识长期地下采空对层状山体的扰动作用,对大型灰岩山体防灾减灾与风险区划具有重要的现实意义。The rockslide of the steeply inclined rock layer at Jiguanling in Wulong, Chongqing was studied.FLAC3 D was used to simulate the progressive failure process of the steeply inclined rocks induced by underground mining,i.e.,from the rock bending,to interbed shearing,toppling,toe breakout and finally sliding. It was considered that the rockslide at Jiguanling exhibited a compound failure mode of stratified rock mass with toppling and sliding. Simulation results showed that:(1) Under the long-term gravitational effect,the steep slope creeped along the mountain ridge and tensile cracks were gradually produced. Meanwhile, due to the slope situated near the anticline core areas,the stress concentration resulted in the bending deformation of the covering strata.(2) The long-term karstification accelerated the development and widening of slope fissures.(3) The coal mining induced the stress redistribution at Jiguanling mountain ridge,the stratum separation occurred gradually inthe overlying rock mass, cracks were formed in the underlying rock mass, and the strength of rock mass was gradually reduced.(4) And after the gradual mining out of coal,the deformation of overlying rock mass increased sharply till the toppling and failure occurred,which squeezed the underlying rock mass and led to the shear failure and finally the collapse-debris flow was formed.

关 键 词：边坡工程 陡倾层状山体 横向斜坡 地下采空 数值分析 倾倒滑移 

分 类 号：P642.22[天文地球—工程地质学]