分散性土的抗剪强度特性试验研究  

Experimental research on shear strength characteristics of dispersive clay

作　　者：唐自强[1] 党进谦[1] 樊恒辉[1] 李凌芸[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《岩土力学》2014年第2期435-440,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.50979094);西北农林科技大学青年学术骨干项目(No.08);西北农林科技大学基本科研业务费(No.QN2009089)

摘　　要：分散性土是一种具有特殊工程性质的土,其典型的性质为抗渗性能差,耐冲蚀能力低,在纯水中具有很高的分散性。目前,人们对于分散性土的研究主要集中在鉴定、抗渗和改良等方面,而对其抗剪强度特性的研究很少。采用三轴CU试验研究不同初始条件下分散性土的抗剪强度特性。结果表明:分散性土的应力-应变曲线在小围压、低含水率和高干密度的状态下呈应变软化型,在围压较大、含水率较高的情况下呈弱硬化型或硬化型;黏聚力和内摩擦角均随含水率的增大而减小,并且干密度越大受水分影响越强烈;黏聚力随干密度的增大而增大,在低含水条件下,黏聚力的增幅较大,而在高含水条件下,黏聚力的增幅则较小;内摩擦角随干密度的增大有少量增大。Dispersive clay is a kind of soil with special engineering properties, and with typical features of poor impermeability, low erosion resistance ability, very high dispersiveness when it is in pure water. In recent years, the study of dispersive clay in the field mainly focuses on identification, penetrability, betterment and other aspects;however, the studies of shear strength properties are rare. In this paper, the conventional triaxial compression consolidated undrained （CU） test is adopted to study the dispersive clay’s shear strength characteristics under different initial conditions. The results show that： dispersive clay’s stress-strain curves present the softening type when it is under the conditions of small confining pressure, low moisture content and high dry density;but it changes into the weak hardening type or hardening type when it is under the conditions of large confining pressure and high moisture content. Dispersive clay’s cohesion and internal frictional angle all decrease while the moisture content increases. In addition, the higher the dry density is, the stronger influence of moisture has on the clay’s cohesion and internal frictional angle;its cohesion increases with the increase of dry density;and it has a larger increment under the low moisture content condition compared to that under the high moisture content conditions;internal frictional angle has a small increment with the increasing of dry density.

关 键 词：分散性土 抗剪强度 含水率 干密度 

分 类 号：TU411[建筑科学—岩土工程]