基于反复直剪试验的强膨胀土强度特性研究  

Study on Strength Characteristics of Strong Expansive Soil Based on Repeated Direct Shear Test

作　　者：李云鹏 林一芃 张晶旭 LI Yun-peng;LIN Yi-peng;ZHANG Jing-xu(Land and Resources Exploration Center of Hebei Bureau of Geology and Mineral Resources Exploration(Hebei Mine and Geological Disaster Emergency Rescue Center),Shijiazhuang 050081,China)

机构地区：[1]河北省地质矿产勘查开发局国土资源勘查中心(河北省矿山和地质灾害应急救援中心),河北石家庄050081

出　　处：《河北地质大学学报》2024年第1期86-91,共6页Journal of Hebei Geo University

基　　金：河北省自然科学基金项目(D2019403182)。

摘　　要：利用ZJ型四联应变控制式直剪仪对南水北调邯郸段不同初始含水率的重塑强膨胀土进行反复直剪试验,设置初始含水率分别为15%、20%、25%、饱和4种状态,研究含水率对其抗剪强度的影响。研究结果表明:初始含水率相同时,峰值及残余强度均随竖向应力的增长而增长;竖向应力相同时,强度随含水率的增长而降低。强膨胀土的抗剪强度指标随着含水率的增长而降低,且可能存在一个含水率的临界值使强度发生明显衰减,强度指标快速降低,研究区膨胀土强度受初始含水率的影响在实际工程中应当引起重视。Repeated direct shear tests of remolded expansive soils with different initial moisture contents in Handan section of South-to-North Water Diversion Project were carried out by using ZJ type four-way strain controlled direct shear apparatus,the set initial moisture content of 15%,20%,25%,and saturation,respectively,to study the effect of moisture content on shear strength.The results show that the peak value and residual strength increase with the increase of vertical stress when the initial water content is the same.When the vertical stress is the same,the strength decreases with the increase of water content.The shear strength index of strong expansive soil decreases with the increase of water content,and there may be a critical value of water content to make the shear strength index mutate,the influence of initial moisture content on the strength index of strong expansive soil in the study area should be paid attention to.

关 键 词：峰值强度 残余强度 强膨胀土 初始含水率 竖向应力 

分 类 号：TU443[建筑科学—岩土工程]