砂质原状黄土强度各向异性试验研究  

Experimental Investigation on Anisotropy of Shear Strength for Undisturbed Sandy Loess

作　　者：王华雄 蔡国庆[1,2] 韩博文 李舰[2] 赵成刚[2] WANG Huaxiong;CAI Guoqing;HAN Bowen;LI Jian;ZHAO Chenggang(Key Laboratory of Urban Underground Engineering of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]城市地下工程教育部重点实验室,北京100044 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《水利与建筑工程学报》2021年第2期24-29,共6页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金项目(51678041;51722802;U1834206);北京市自然科学基金面上项目(8202038)。

摘　　要：为研究各向异性条件下原状黄土的变形及强度特性,针对取自北京市郊某施工现场原状黄土试样,在保持土样天然含水率条件下,分别对水平方向和竖直方向原状土样开展了固结不排水和固结排水三轴剪切试验。试验结果表明:试验用原状黄土黏粒含量相对较低,砂粒含量则偏高;其抗剪强度在水平方向和竖直方向表现出明显的各向异性。对于固结不排水试验,竖直方向的内摩擦角和黏聚力均大于水平方向,当增大围压时,水平方向和竖直方向试样的最大偏应力以及破坏应变值都呈上升趋势;对于固结排水试验,竖直方向的内摩擦角大于水平方向,而黏聚力则是水平方向大于竖直方向,当增大围压时,水平方向和竖直方向试样的最大偏应力都呈上升趋势,水平方向试样的破坏应变值呈上升趋势,然而竖直方向的试样则呈现出先下降后上升的变化趋势。In order to analyze the deformation and strength characteristics of the undisturbed loess under the anisotropic condition,the consolidated undrained and consolidated drained triaxial shear tests were carried out on the horizontal and vertical undisturbed loess samples taken from a construction site in Beijing area under the condition of keeping the natural moisture content of the soil samples.The results show that the clay content of undisturbed loess in Beijing is lower than that in other areas,while the sand content is higher,and its shear strength shows obvious anisotropy in horizontal and vertical directions.In the consolidated undrained test,the internal friction angle and cohesion in the vertical direction are greater than that in the horizontal direction.When the confining pressure increases,the maximum deviatoric stress and failure strain of the specimens in horizontal and vertical directions will also increase.In the consolidated undrained test,the maximum deviator stress and failure strain in the vertical direction and the horizontal direction gradually increase.When the confining pressure increases,the maximum deviatoric stress of the specimens in horizontal and vertical directions also increase.The failure strain of the horizontal specimens increase gradually,while that of the vertical specimens decrease first and then increase.

关 键 词：原状黄土 各向异性 抗剪强度 三轴试验 

分 类 号：TU411[建筑科学—岩土工程]