矿区大型滑坡体力学机理及地质演化模式研究  

Study on mechanics mechanism and geological evolution model of large landslide in mining area

作　　者：李巧刚[1] 张树东 吴斌 LI Qiaogang;ZHANG Shudong;WU Bin(Beijing Institute of Geology,Bejing 100120,China;The State Key Laboratory for Geo-Mechanics and Deep Underground Enginering,China Unirersity of Mining and Technology-Bejing,Beijing 100083,China)

机构地区：[1]北京市地质研究所,北京100120 [2]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室,北京100083

出　　处：《煤炭科学技术》2020年第3期214-220,共7页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51674135)。

摘　　要：基于很多煤矿位于山区,常发生山体滑坡灾害,对矿区居民的正常生产生活造成严重影响,因此对滑坡灾害成因的研究对地质灾害的防灾减灾工作具有重要意义,以北京市房山区大安山矿军红路滑坡为例,采用微观电镜扫描(SEM)和TTRⅢ多功能X射线衍射仪对组成滑坡体的岩石微观结构和成分进行了分析测定,并在2000 kN岩石单三轴实验系统对滑坡体岩石力学性质进行了测试。研究结果表明:滑坡体主要由侏罗系南大岭组变质玄武岩、二叠系石盒子组灰白色含砾石英砂岩构成,这几种岩石中,黏土矿物含量较高,玄武岩为36.1%、砂岩为40.6%、砾岩为18.5%;军红路滑坡是典型的降雨诱发型滑坡,连续多日降雨造成雨水沿后缘裂缝入渗,软化并降低软弱夹层强度,经历了卸荷拉裂、时效变形、局部溃屈和整体高速滑坡4个阶段;组成军红路滑坡的多种岩石的矿物成分中黏土矿物含量较高,水对岩石力学特性影响显著,单轴强度饱水弱化分别达玄武岩54.2%、砂岩为40.0%、砾岩为35.2%,这对于该滑坡在降雨作用下发生及迅速启动有至关重要的作用;结构面是影响岩石力学特性的重要因素,在变形过程中,岩石沿着软弱结构面先发生破坏,降雨又进一步加速了结构面的破坏,是导致军红路滑坡发生的另一个原因。Many coal mines are located in the mountainous area,landslide disasters often occur,which seriously affects the normal production and life of the residents in the mining areas.Therefore,the study on the causes of landslide disaster is of great significance for the prevention and mitigation of geological disasters.The Junhong Road landslide in Fangshan District of Beijing was taken as an example in this paper.The microstructure and composition of the rocks that make up the landslide were analyzed by using micro-electron microscopy(SEM)and TTRⅢmulti-function X-ray diffractometer.The 2000 k N rock single triaxial test system was used to analyze the landslide rocks.The mechanical properties were tested.The results show that the landslide body is mainly composed of metamorphic basalt from the Jurassic Nandaling Formation and gray-white gravel quartz sandstone from the Permian Shihezi Formation.Among these types of rocks,the clay mineral content is relatively high,with basalt of 36.1%,sandstone of 40.6%and conglomerate of 18.5%.Junhong Road landslide is a typical rainfall-induced landslide,which has experienced four stages:unloading tension crack,time-dependent deformation,local buckling and overall high-speed landslide.The content of clay minerals in the mineral components of several rocks that constitute the Junhong Road landslide is relatively high,and water has a significant effect on the mechanical properties of the rock.The uniaxial strength weakening of saturated water is 54.2%for basalt,40.0%for sandstone and 35.2%for conglomerate respectively,which play important roles in the occurrence and rapid start-up of the landslide under the action of rainfall.The structural surface plane is an important factor affecting the mechanical properties of rock.During the deformation process,the rock along the weak structural plane first breaks,and the rainfall further accelerates the failure of the structural plane,which is another reason for the occurrence of the Junhong Road landslide.

关 键 词：滑坡体 降雨 力学机理 结构面 

分 类 号：P642.22[天文地球—工程地质学] TD313[天文地球—地质矿产勘探]