基质吸力对重塑红黏土抗剪强度影响的试验研究  

Experimental research on the influence of matric suction on the shear strength of remolded red clay

作　　者：李涛[1] 刘波[1] 杨伟红[1] 黄佩格[1] 周妍[1] 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《中国矿业大学学报》2013年第3期375-381,共7页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(50974126);博士学科点新教师类专项科研基金项目(20100023120003);中央高校基本科研业务费专项资金项目(2009QL02)

摘　　要：通过室内剪切试验,得到了非饱和重塑红黏土的黏聚力和内摩擦角随水质量分数变化的规律;采用滤纸法进行了基质吸力的量测,得到不同干密度下的水-土特征曲线;基于试验结果,获得了考虑基质吸力的破坏包络面,初步分析了基质吸力对红黏土剪切强度的影响.结果表明:该类红黏土黏聚力随含水量的增加按Gauss函数变化;内摩擦角随含水量的增加符合Sigmoidal函数,在水质量分数为0时,达到最大值;有效内摩擦角φ′在等基质吸力平面上为一定值,在不同的基质吸力平面上随着基质吸力的增加逐渐增大;φb具有随基质吸力的增加而先不变后减小的特征,且随净法向应力的增加而增大;基质吸力在高净法向应力时,对抗剪强度的贡献较大.Using the shear test in laboratory concluded that the cohesion and internal friction angle of unsaturated remolded red clay varied with water content.The use of filter paper method measured the matric suction,and got the water-soil characteristic curve under different dry densities.Based on the experimental results,the failure envelope plane in consideration of matric suction was obtained,and the influence of matric suction on the shear strength of red clay was analyzed preliminarily.The results show that： the cohesion of this kind of red clay increases with water content in terms of Gauss Function,while the internal friction angle increases with water content on the basis of Sigmoidal Function;when the water content is equal to 0,the maximum value gets;the effective internal friction angle φ′ is a constant value in the equivalent matric suction plane,and the angle increases with the increase of matric suction in the different matric suction planes;parameter φb is firstly a constant,then decreasing with the increase of matric suction,but increases with the increase in net normal stress;the matric suction contributes greatly to the shear strength under the high net normal stress.

关 键 词：非饱和重塑红黏土 基质吸力 抗剪强度 试验研究 

分 类 号：TU411.7[建筑科学—岩土工程]