增湿条件下膨胀土边坡稳定性影响因素有限元分析  

Finite Element Analysis of Influencing factors on Stability of Expansive Soil Slope Subject to Humidification Induction

作　　者：张硕[1,2] 蒋良潍 罗强[1,2] 李傲赢[1,2] 司光武 ZHANG Shuo;JIANG Liang-wei;LUO Qiang;LI Ao-ying;SI Guang-wu(Key Laboratory of High-speed Railway Engineering,Ministry of Education,Chengdu 610031,China;School of CMI Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]高速铁路线路工程教育部重点实验室,成都610031 [2]西南交通大学土木工程学院,成都610031

出　　处：《铁道标准设计》2018年第10期31-36,共6页Railway Standard Design

基　　金：中央高校基本科研业务费专项资金资助(2682014CX064);国家重点基础研究发展计划项目(973计划)(2013CB036204)

摘　　要：为研究雨季土体增重、强度降低及膨胀作用这三项影响膨胀土边坡稳定性作用因素的主次关系,基于热膨胀比拟增湿膨胀原理,考虑水平、竖向间的差异膨胀性,推导土体增湿膨胀的应力-应变方程,利用无荷膨胀率试验有限元模型进行参数验证;针对某铁路膨胀土边坡,建立ABAQUS有限元强度折减模型,采用正交试验极差分析法,研究含水率变化条件下边坡稳定性影响因素的作用效应及敏感性。研究表明:当初始含水率较低时,土体强度降低对边坡稳定性的影响最为显著,膨胀作用次之,土体增重影响相对较小,随土体初始含水率增大,膨胀作用、土体增重的影响减弱;土体初始含水率较低时,考虑土体水平、竖向间差异膨胀性计算得到的稳定安全系数较传统的各向同性膨胀假设结果低0.11~0.13,随含水率的升高,差异膨胀性的影响减小。In order to study the primary and secondary relations of the factors affecting the stability of expansive soil slope in rainy season,such as weight gain,strength reduction and expansion effect,the stress-strain equation of soil humidification is deduced based on the principle of thermal expansion comparable to humidification expansion and in view of the differential expansion between the horizontal and the vertical,and the finite element model is used to verify the experimental results of free expansion ratio. A ABAQUS finite element strength reduction model is established for a railway slope of expansive soil and the effect and sensitivity of influencing factors on the stability of slope subject to the changes of water content are studied by means of the range method of orthogonal test. Studies results show that when initial water content of soil is low the effect of soil strength reduction on the stability is the most obvious followed by the effect of expansion,ant soil weight gain is relatively weak. With the increase of initial water content of soil,the effects of expansion and soil weight gain are reduced. If the safety factor of stability considering the differential expansion of soil is 0. 11 ~ 0. 13 lower than that of the traditional isotropic expansion hypothesis when soil initial water content is lower,the effect of differential expansion is reduced with the increase of water content.

关 键 词：膨胀土边坡 增湿 稳定性 有限元强度折减法 正交试验 

分 类 号：U416.14[交通运输工程—道路与铁道工程]