防灾减灾工程学报2017，Vol.37Issue(6)：892-899,8.DOI:10.13409/j.cnki.jdpme.2017.06.006
基于偏应力增量的边坡开挖松动区的确定方法
A Method to Determine the Disturbed Zone of Cutting Slope Based on Deviatoric Stress Increment
摘要
Abstract
For the slope failure caused by excavation unloading effect,the reasonable stability analyses result always can not be obtained by the traditional limit equilibrium method.With loosened zone as the stability analysis object for cutting slope,deviatoric stress increment was chosen as the analysis indicator and its numerical analysis method to determine the range of loosened zone was put forward.The loosened zone was defined as the sum of elastic relaxation zone and plastic flow zone which should distribute continuously and have adverse effect on slope stability.The adjustment of deviatoric stress field is the main reason for slope failure after excavation.Calculation program of deviatoric stress and its increment was written in FLAC3D software.Taking a dip bedded cutting slope as example,the development process of deviatoric stress and displacement during the excavation was calculated by the FLAC3D.The results indicate that there exists a remarkable correlativity between the deviatoric stress and displacement.The deviatoric stress increment contours were characterized by abnormal phenomena which contain local salience and partition of positive and negative values etc.The sequential connection line of salience vertexes is the boundary line between zones in which deviatoric stress redistribution is abnormal or not,and so it can be considered the inner boundary of loosened zone.The proposed method can provide some references for the stability analyses and pre-reinforcement design of cutting slopes.关键词
边坡/开挖卸荷效应/松动区/偏应力增量/变形破坏Key words
slope/excavation unloading effect/loosened zone/deviatoric stress increment/deformation failure分类
交通工程引用本文复制引用
胡田飞,杜升涛,师亚龙..基于偏应力增量的边坡开挖松动区的确定方法[J].防灾减灾工程学报,2017,37(6):892-899,8.基金项目
中央高校基本科研业务费项目(C17JB00520)、国家重点基础研究发展计划(2012CB026104)资助 （C17JB00520）
