基于环剪试验的黄土完全软化强度研究  

Research on fully softened strength of loess based on ring shear tests

作　　者：李姝[1] 张立展 许强[1] 束骞[1] 彭大雷[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：《人民长江》2015年第21期84-87,共4页Yangtze River

基　　金：国家重点基础研究发展"973"计划(2014CB744703;2013CB733200);国家杰出青年科学基金项目(41225011)

摘　　要：甘肃省永靖县黑方台地区灌溉水下渗导致地下水位抬升,加之季节性冻结滞水促滑效应的影响,进而诱发了大量黄土滑坡。为了进一步研究地下水长期作用对黄土强度的影响,采用环剪仪装置开展了不同饱水时间下(1,3,5,7,10,15,20 d)重塑黄土的强度试验研究。试验结果显示,黄土强度饱水时间曲线呈"勺形",指出"勺底"数值更符合完全软化强度的定义,并且从水、土相互作用的微观角度对曲线形状作出了合理解释。初步认为,该地区饱水3 d左右的抗剪强度接近于完全软化强度。The infiltration of irrigation water in Heifangtai loess plateau, Yongjing County Gansu Province, elevates the under- ground water level and triggers dozens of loess landslides due to sliding - promoting effect of seasonal frozen stagnant water. In or- der to study the long term influence of groundwater on strength of loess, the ring shear apparatus was used to study the shear strength variation of saturated remodeled loess with different saturation time （1, 3, 5, 7, 10, 15d and 20d）. The test result shows that the shape of strength - saturation time curve is in the shape of ＂ spoon＂, and the value at the spoon bottom conforms with the definition of fully softened strength. Then the curve shape is analyzed in term of interactions of water and loess in a micro perspective. It is preliminarily concluded that the shear strength of 3d saturated time closes to the fully softened strength in Hei- fangtai area.

关 键 词：环剪试验 黄土 完全软化强度 内摩擦角 

分 类 号：P642[天文地球—工程地质学]