地震和降雨耦合作用下黄土边坡失稳滑移的振动台试验研究  

The shaking table test of the instability sliding of loess slope under the coupling effects of earthquake and rainfall

作　　者：王兰民[1,2] 蒲小武 吴志坚[1,2] 孙军杰[1,2] 王平[1,2] 柴少峰[1,2] 徐舜华[1,2] 邓津[1,2] 

机构地区：[1]中国地震局兰州地震研究所黄土地震工程重点实验室,甘肃兰州730000 [2]中国地震局兰州地震研究所甘肃省岩土防灾工程技术研究中心,甘肃兰州730000

出　　处：《岩石力学与工程学报》2017年第A02期3873-3883,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51478444;41472297;51578518)~~

摘　　要：为了研究黄土边坡在地震和降雨耦合作用下的动力响应特征、变形演化过程以及失稳破坏机制,开展天然状态、降雨100 mm黄土边坡2种模型试验,对比分析降雨前后两类边坡模型的宏观变形、加速度、孔压、土压力等相关物理量的变化特征。结果表明:降雨后黄土边坡模型自振频率降低,阻尼比增大,地震动放大效应增强;强震作用下,坡顶区域土体震陷、液化,后续地震动作用下液化土体还会出现顺坡向滑移;根据边坡模型宏观变形、孔压及土压力变化,其失稳破坏过程可划分为:弹性动变形阶段、残余变形快速增加阶段、液化滑移阶段、蠕滑阶段4个阶段,不同阶段土体宏观变形、孔压、土压力各自有其特点。To explore dynamic response features,deformation evolution process and failure mechanism of loess slope under the coupled effect of earthquake and rainfall,two model tests of loess slope with 100 mm rainfall and natural state were carried out to compare and analyze change features of macroscopical deformation and related physical quantities such as acceleration,pore pressure and soil pressure,etc.The results indicate that natural vibration frequency in loess slope model after rainfall is reduced as well as damping ratio is increased and amplification effects of seismic oscillation are enhanced.Under effect of strong shock,the soil in the top of the slope are seismically settled and liquified and liquified soil would slip along the slope under follow-up seismic oscillation.In line with changes in macroscopical deformation,pore pressure and soil pressure in the slope model,the failure process can be divided into four phases,namely elastic deformation phase,rapid increase phase of residual deformation,liquification slipping phase and creeping phase.Macroscopical deformation,pore pressure and soil pressure of the soil in different phases are with their own characteristics.

关 键 词：边坡工程 耦合作用 动力响应 失稳机制 振动台 模型试验 相似比 

分 类 号：P64[天文地球—地质矿产勘探]