降雨开挖诱发顺层岩质滑坡稳定性与堆积特征  

Stability and accumulation characteristics of bedding rock landslides inducedby rainfall-excavation

作　　者：崔宇寒 顾东明 余海兵[1,2] 吕豪[1] 谢昭宇 CUI Yuhan;GU Dongming;YU Haibing;LYU Hao;XIE Zhaoyu(Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;Badong National Geological Disaster Observation and Research Station,China University of Geosciences(Wuhan),Wuhan 430074,China;Hubei Daoze Geotechnical Engineering Co.,Ltd.,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]中国地质大学(武汉)巴东国家地质灾害观测研究站,湖北武汉430074 [3]湖北道泽岩土工程有限公司,湖北武汉430074

出　　处：《人民长江》2024年第9期156-164,共9页Yangtze River

基　　金：国家自然科学基金项目(42090054)。

摘　　要：在自然环境与工程建设中,顺层岩质滑坡因其易发、频发、突发等特征,一直是地质灾害领域研究热点之一。以湖北省建始县大包山滑坡为例,综合现场调查、无人机(UAV)摄影等手段,开展含软弱夹层结构面强度弱化规律试验,考虑强度弱化的降雨-开挖联合作用,进行边坡动态稳定性与堆积特征数值模拟分析,探讨边坡破坏诱因,揭示边坡变形机制。主要结论如下:①自然边坡在天然、暴雨工况下稳定性系数分别为1.35和1.20,开挖边坡在天然、暴雨工况下稳定性系数分别为1.04和0.90;最不利工况下,边坡第四级开挖后,发生失稳破坏,诱因为降雨-开挖联合作用;②大包山滑坡破坏模式为典型的滑移-拉裂破坏,即滑坡体前缘侧向隆起,中后缘牵引式滑动,后缘发生拉裂破坏,滑坡体沿软弱结构面整体性顺层平面滑动;③大包山滑坡的变形破坏和启滑运动堆积过程可划分为5个阶段,即裂缝发展贯通阶段、启滑动态响应阶段、整体高速滑动阶段、平台碰撞制动阶段、堆积侧向挤滑阶段;滑坡前缘于坡脚处堆积,堆积距离约15~25 m,整体滑移水平距离约15 m,滑坡最大位移量高达30 m。研究成果对类似顺层岩质滑坡研究具有一定参考价值。In the natural environment and engineering construction,bedding rock landslides have always been one of the research hotspots in the field of geological disasters due to their characteristics of easy occurrence,frequent occurrence,and sudden occurrence.Taking the Dabaoshan Landslide in Jianshi County,Hubei Province as an example,the strength weakening law test of the structural plane with weak interlayer was carried out by field investigation and UAV photography.Considering the combined effect of rainfall and excavation,a numerical simulation analysis of dynamic stability and accumulation characteristics was conducted to explore the causes of slope failure and reveal the deformation mechanism of the slope.The main conclusions are as follows:①The stability coefficients of natural slopes under natural and rainstorm conditions are 1.35 and 1.20,respectively.The stability coefficients of excavated slopes under natural and rainstorm conditions are 1.04 and 0.90,respectively.Under the most unfavorable conditions,the instability failure occurs after the fourth stage of excavation of the slope,and the inducement is the combined effect of rainfall and excavation.②The failure mode of the slope is a typical slip-crack failure.That is,the front edge of the landslide body is laterally uplifted,the middle and rear edges are traction sliding,the rear edge is tensile failure,and the landslide body is sliding along the weak structural plane.③The deformation,failure,and accumulation process of the Dabaoshan Landslide can be divided into five stages,namely,the crack development and penetration stage,the dynamic response stage,the overall high-speed sliding stage,the platform collision braking stage,and the accumulation lateral extrusion sliding stage.The front edge of the landslide accumulates at the foot of the slope,the accumulation distance is about 15~25 m,the overall slip horizontal distance is about 15 m,and the maximum displacement of the landslide is up to 30 m.The research results have a certain reference value for t

关 键 词：顺层岩质滑坡 降雨 边坡开挖 数值模拟 强度弱化 大包山滑坡 

分 类 号：P642.22[天文地球—工程地质学]