应变软化边坡渐进破坏及其稳定性初步研究  

A preliminary study of the progressive failure and stability of slope with strain-softening behaviour

作　　者：沈华章[1] 王水林[1] 郭明伟[1] 葛修润[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试验室,湖北武汉430071

出　　处：《岩土力学》2016年第1期175-184,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51179185;No.41472289;No.41302236);国家重点基础研究发展计划(973)项目(No.2014CB047100)~~

摘　　要：采用应变软化本构模型和矢量和法,提出了一种模拟应变软化边坡渐进性破坏过程的分析方法。该方法可得到应变软化边坡的坡体材料强度参数、滑面状态、稳定安全系数、边坡破坏状态的变化过程,据此可分析边坡的渐进破坏。采用所提方法对应变软化材料边坡算例进行了分析,并与3种极限平衡法进行了对比,结果表明:(1)滑面矢量和安全系数介于传统极限平衡法峰值安全系数与残余安全系数之间,滑面强度参数部分处于峰值状态、部分处于残余状态,弥补了传统极限平衡法不能得到真实的应变软化边坡安全系数的缺陷。(2)强度参数弱化的区域与边坡破坏区域位置一致,坡脚处滑面最先出现软化,随着塑性剪切破坏的发展,其由软化状态变为残余状态,邻近部分滑面开始出现新的软化,接着进入残余状态,边坡破坏由坡脚向坡顶发展,随着这个过程的持续进行,边坡的渐进性破坏不断发展,边坡安全系数不断降低,直至渐进性破坏过程结束。(3)随着残余软化参数的增加,滑面位置逐渐变浅,矢量和法安全系数逐渐增加。该方法能够较好地分析边坡的渐进性破坏过程,具有较好的应用前景。By means of the vector sum method and strain-softening constitutive model, a method for progressive failure analysis of strain-softening slopes is developed, which can show the processes of variations of the strain-softening slope safety factor, strength parameters, and failure state of slope and slip. Based on this, progressive failure progress of slope with strain-softening behavior can be simulated. Numerical results are compared to those of the limit equilibrium methods, showing the validity of the proposed method. It is shown that the vector sum method safety factor are in between peak and residual safety factors by the limit equilibrium method; the strength parameters of the main part of slip surface are at the peak value, and the other at the residual value; the proposed method compensates for the defect of the traditional limit equilibriummethods failing to provide a realistic safety factor of slope with strain-softening behavior. The strength weakening zone is found to be consistent with the failure zone in the slope. In the shearing process, the strain-softening behavior first occurs at the toe of the slope, and the strength parameters reduce to the residual value at the toe of the slope; then new strain-softening behaviors occur at the adjacent zone and then enter the residual state; finally the progressive failure develops from the toe of slope to the top of the slope. As the process continues, the progressive failure gradually develops and the safety factor decreases until the end of the progressive failure is reached. The safety factor increases with the increase of residual soft parameter, and the position of critical slip surface moves towards shallow, resulting in an increase of the vector sum method safety factor.

关 键 词：渐进性破坏 矢量和法 应变软化 边坡稳定性 

分 类 号：TU473.1[建筑科学—结构工程]