牵引式滑坡的破坏机制及其加固措施探讨——以某高速公路牵引式滑坡为例  

Discussion on failure mechanism of retrogressive landslide and its reinforcement measures:taking a certain expressway retrogressive landslide for example

作　　者：宋东日[1] 任伟中[1] 沈波 徐志忠 周英博[1] 张思渊[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [2]恩施州公路管理局,湖北恩施445000

出　　处：《岩土力学》2013年第12期3587-3593,共7页Rock and Soil Mechanics

基　　金：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室重点项目(No.SKL208064);中国科学院知识创新工程重要方向项目(No.KZCXZ-YW-151)

摘　　要：牵引式滑坡在山区公路滑坡中占有相当的比重,其治理工程往往耗资巨大、环境破坏严重。针对某高速公路牵引式滑坡,通过地质调查、变形迹象分析、岩土体应力-应变分析及数值模拟等方法,指出具体破坏机制为:(1)坡脚开挖致使阻滑关键块体缺失,应力集中导致剪切应变软化;(2)地表降水与地下水对岩土体物理力学性能的改造;(3)滑体变形不协调,导致拉裂缝产生,滑坡后缘得以继续向后扩展。目前监测表明,已施工的组合加固措施效果良好。最后讨论挖方引起的牵引式滑坡的工程地质特征,对牵引式滑坡进行评价应坚持安全系数分区原则,滑坡总体加固应按安全系数控制,同时对后缘加固按位移控制。The retrogressive landslide occupies a considerable proportion among expressway landslides in the mountain area. The reinforcement projects often cost enormously and the environment around is usually damaged severely. Taking a certain expressway retrogressive landslide for example, through approaches of geological survey, deformation investigation, stress-strain behavior analysis and numerical modeling, the failure mechanism is confirmed as follows： （1） the loss of resisting key block is caused by slope foot excavation, shear strain softening is induced by stress concentration; （2） physico-mechanical properties alternation of the rock and soil mass are remolded by the surface rainfall and groundwater; （3） tensile cracks are fromed deformation incompatibility and its expanding backward. The monitoring results show that the applied combined reinforcement measures work well. The geological characteristics of excavation-induced retrogressive landslides are discussed. A principle that ＂the safety factor should be calculated by section should use to evaluate retrogressive landslide; the reinforcement of the whole landslide should be controlled by the predetermined safety factor; while the reinforcement of landslide rear should be controlled by displacement.

关 键 词：牵引式滑坡 滑坡范围 加固措施 位移控制 

分 类 号：U416[交通运输工程—道路与铁道工程] TU42[建筑科学—岩土工程]