吸力路径对非饱和土力学性质的影响  

Effect of suction path on mechanical behaviors of unsaturated soils

作　　者：宋友建[1] 胡新丽[1] 郭利娜[1] 张国超[1] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《水文地质工程地质》2013年第5期64-68,共5页Hydrogeology & Engineering Geology

基　　金：国家重点基础研究发展计划"973"项目(2011CB710604)

摘　　要：基质吸力的存在使得土的工程性状变得十分复杂。非饱和土的力学性质,不仅受基质吸力及竖向荷载等应力状态的影响,吸力路径也起着不可忽视的作用。为了探讨不同吸力路径对非饱和土应力-应变关系和强度的影响,采用非饱和土直剪仪对不同吸力路径固结平衡的非饱和土样进行直剪试验,获得其固结量及应力-应变关系,得到了不同吸力路径对非饱和土抗剪强度的影响规律。试验结果表明:在相同的竖向荷载条件下,非饱和土的抗剪强度随着吸力的增加明显增大。在相同吸力及竖向荷载条件下,经历过较高吸力历史的试样固结量和前期剪切强度明显增大。The existence of matric suction make the soil engineering properties become very complex.The stress state such as vertical load and suction has an important influence on the soil mechanical property.Suction path also plays an important role in the soil mechanical property.In order to explore the effect of different suction paths to stress-strain behaviour and shear strength of unsaturated soil,direct shear tests are conducted for the unsaturated soil using direct shear apparatus to control different suction paths to balance the unsaturated soil samples,and the parameters of consolidation and stress-strain are obtained.The influence law of the different matric suction paths to mechanical property of unsaturated soil issummaried.The test results show that when in the same condition of vertical load,the shear strength increases obviously by the suction;when in the same condition of vertical load and suction,the consolidation and beginning shear strength of the test sample,which has experienced a large matric suction,is larger.

关 键 词：非饱和土 吸力路径 抗剪强度 固结量 剪切体变 

分 类 号：TU43[建筑科学—岩土工程]