强震触发黄土滑坡发生机制试验  

Laboratory Study of the Mechanism of Loess Landslide Caused by Violent Earthquake

作　　者：芮雪莲 裴向军[1] 张晓超[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《实验室研究与探索》2016年第1期23-26,154,共5页Research and Exploration In Laboratory

基　　金：中国地质调查局项目(1212011140005)

摘　　要：为了进一步研究不同地震破坏程度后黄土的变形特性及稳态强度,通过MTS土动三轴仪进行了不同围压(100、150、200 k Pa)、不同动应变(0,1%、2%、3%)条件下的饱和黄土静力剪切试验。结果表明:在相同试样条件下,应力路径对稳态强度影响极小,不同震动破坏程度的试样在试验结束后的残余强度几乎相等;黄土液化后的稳态强度随着初始孔隙比的减小而增加;饱和度主要对黄土的黏聚力产生影响;初始有效固结压力与稳态强度有良好的拟合关系。比较震后斜坡重力驱动剪应力与稳态强度的关系,可判断斜坡会否发生破坏。Residual strength plays a major role for the stability of the loess slope after the earthquake. A series of post liquefaction triaxial compression tests have been conducted to simulate the loess slope deformation characteristic and residual strength after liquefaction. Saturated loess under static shear tests has been conducted in the conditions of different pressures（ 100; 150; 200 k Pa） and different dynamic strain（ 0; 1%; 2%; 3%） by MTS dynamic tri-axial instrument. Testing result indicates that,for the same sample,stress path has little effect on residual strength,though the destruction levels of samples（ 0; 1%; 2%; 3%） are different. The residual strength of samples after the experiment are almost equal. There is a negative correlation between initial void ratio,saturation and residual strength. The relationship of the initial consolidation stress and residual strength can be started with a quadratic function. According to the test result,the residual strength can be used to analyze the mechanism of Shi Beiyuan loess slide.

关 键 词：黄土滑坡 液化后变形 稳态强度 影响因素 

分 类 号：P642.22[天文地球—工程地质学]