四川王山-抓口寺滑坡成因机制及滑动过程分析  

Formation mechanism and failure process of Wangshan-Zhuakousi Landslide in Sichuan Province

作　　者：李俊峰 陈红旗[1] 刘红岩[2,3] LI Junfeng;CHEN Hongqi;LIU Hongyan(China Institute for Geo-Environmental Monitoring,Beijing 100081,China;School of Engineering ＆ Technology,China University of Geosciences（Beijing）,Beijing 100083,China;School of Engineering,Tibet University,Lhasa,Tibet 850000,China)

机构地区：[1]中国地质环境监测院,北京100081 [2]中国地质大学(北京)工程技术学院,北京100083 [3]西藏大学工学院,西藏拉萨850000

出　　处：《中国地质灾害与防治学报》2018年第4期30-39,共10页The Chinese Journal of Geological Hazard and Control

基　　金：国家自然科学基金(41162009);国土资源部公益性行业科研专项:突发地质灾害应急响应支撑关键技术研究(201211055)

摘　　要：以王山-抓口寺大型岩质滑坡为例,在对滑坡变形破坏特征及周边工程地质条件现场调查和研究的基础上,通过地质分析手段获取区内滑坡体从缓慢变形到失稳破坏全过程的基本信息,提出滑坡演变概化地质模型,并结合非连续变形分析方法模拟真实时间和便于分析非连续大变形的特点,建立非连续变性分析(DDA)数值模型,对滑坡体稳定性和滑动全过程进行数值模拟,并对降雨弱化结构面强度参数影响滑坡滑距和速度进行分析。结果表明:王山-抓口寺滑坡主要诱发原因是汛期持续降雨使雨水沿裂隙大量渗入滑体导致滑坡体结构面强度参数降低;同时,滑坡前缘由于前期堰塞湖人工清理和河水自然侧蚀,临空面高达十数米,为滑坡的发生提供了有利条件,最终形成"强降雨-入渗-岩体软化-推拉"破坏模式,属典型的滑移-拉裂型岩质滑坡;参数影响性表明结构面内摩擦角φ对滑坡滑距和滑速影响显著,黏聚力c对滑坡位移和速度影响有限;模拟得到的滑坡最大滑移速度和后缘最大滑动距离与野外调查相符。Based on the analysis of Wangshan-Zhuakousi rock landslide,the deformation,failure process of landslide and its engineering geological conditions have been studied by field investigation and analysis. The slope body＇s general information was collected by analysis of geological survey. With advantages of real time variable employment and large discontinuous simulation by the method of discontinuous deformation analysis（ DDA）,the DDA numerical model was build; the stability and the sliding process of landslide has been carried out with the DDA code; and the sensitivity analysis has been used to study the effects to sliding distance and speed of the landslide because of the rainfall weakening joint strength parameters. It is shown that the main reason of Wangshan-Zhuakousi Landslide is the reduction of mechanical parameters of joints resulted from rainfall; and the rock slope＇s sliding is benefit from the cleaning up of the barrier lake in front of the landslide,an airport surface of more than 10 meters was formed,and the landslide is conformed to be a typical-sliding-tension cnacking and fracturing type. The internal friction angle φ has a significant effect on the sliding distance and speed of the landslide,but the effect of the cohesion c is little. The simulation results inmaximum slip velocity and maximum sliding distance of landslide is consistent with actual field survey.

关 键 词：滑坡 成因机制 数值模拟 非连续变形分析 DDA 

分 类 号：P642.22[天文地球—工程地质学]