开挖与降雨作用下边坡失稳机理及模拟分析  

MECHANISM OF SLOPE FAILURE AND NUMERICAL SIMULATION ANALYSIS UNDER SLOPE EXCAVATION AND RAINFALL INFILTRATION

作　　者：肖超[1] 金福喜[1] 刘海鸿 张可能[1] 

机构地区：[1]中南大学有色金属成矿预测教育部重点实验室地球科学与信息物理学院,长沙410083 [2]湖南交通规划勘察设计院,长沙410083

出　　处：《工程地质学报》2012年第1期37-43,共7页Journal of Engineering Geology

基　　金：湖南省自然科学基金项目(07JJ6070)资助

摘　　要：边坡开挖和降雨通常是导致边坡失稳的重要原因。本文以湖南湘西山区某国道扩建开挖边坡为研究对象,基于现场边坡监测结果和数值模拟分析,研究了在边坡开挖和降雨条件下坡体变形位移的过程。结果表明:边坡的破坏是一个渐变的过程,不同的影响因素对边坡的影响不同。开挖切方是浅层坡体失稳的诱发因素,开挖切方破坏了坡体的应力平衡,使坡体的应力重新分布,并在坡体中产生浅层的滑动面。雨水的入渗是坡体深层滑动面的诱发因素,雨水沿着裂缝渗入坡体,使浅部滑动面上下土体的变形差进一步加大,进而产生浅层牵引式滑动破坏。同时雨水的入渗使碎石土和强风化页岩交界附近产生高孔隙水压力,在水-岩土共同作用逐渐形成软化的滑带土,从而形成深层滑动面。Slope excavation and rainfall infiltration are often important factors affected slope stability.In this paper,the rebuilding of HuNan national highway is studied.Based on monitoring data and numerical analysis,the process of slope deformation is studied during the slope cutting and under rainfall conditions.The results show that the slope failure is a gradual process.Different factors can influence the slope stability and have different functions in the process.Slope excavation is the inciting factor which can lead to the failure of shallow slope body.For the slope is excavated,the stress balance of the slope body is destroyed.Slope body has a redistributed stress state.Then the shallow sliding surface is formed.The rainfall infiltration is the inciting factor leading to the deep sliding surface.The rainfall infiltrates the slope body along cracks.Deformation difference can increase on the both sides of shallow sliding surface.Then the pull-type landslide can be emerged.The high porewater pressure is in the interface between debris and strong weathered shale.The sliding zone is generated under the action of water-soil gradually.Consequently the deep sliding surface is emerged.

关 键 词：边坡开挖 雨水入渗 位移监测 数值分析 边坡稳定性 

分 类 号：TU45[建筑科学—岩土工程]