应力历史对饱和砂土力学性状影响的试验研究  

Experimental study of effect of stress history on mechanical properties of saturated sand under complex stress conditions

作　　者：冷艺[1,2,3] 栾茂田[1,2] 许成顺[4] 马太雷[1,2] 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,大连116024 [2]大连理工大学土木水利学院岩土工程研究所,大连116024 [3]中交水运规划设计院有限公司,北京100007 [4]北京工业大学建筑工程学院,北京100022

出　　处：《岩土力学》2009年第5期1257-1263,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.50579006;No.50639010)

摘　　要：三向应力历史条件的影响是准确预测地基变形的重要参考因素之一。针对相对密度为30%的福建标准砂,利用土工静力-动力液压-三轴扭转多功能剪切仪,进行了复杂条件下应力路径变化的应力控制式单调排水剪切试验。通过控制试验过程的平均主应力保持不变,改变应力历史条件,着重探讨应力历史对饱和砂土剪切强度和应力-应变关系的影响。试验结果表明:当平均主应力一定时,在排水条件下应力历史的改变,对砂土的剪切强度几乎没有影响,但会影响应力-应变特性。弹性轨迹随着中主应力系数和主应力方向角历史的不同而发生变化。引入考虑应力历史同剪切过程之间条件变化的参数,结合试验数据,给出了三维空间中砂土受到应力历史作用后形成的弹性边界的关系表达式。The effect of stress history under three dimensional stress conditions are one of the important phenomena which have to be evaluated for the accurate prediction of ground deformation. Various stress-controlled drained monotonic shear tests on the Chinese Fujian standard sand of relative density 30 % under complex stress conditions with different stress paths are conducted using the soil static and dynamic universal triaxial and torsional shear apparatus. The mean principal stress is controlled unchanged in the process of tests. The stress history conditions are varied so that their influences on shear strength and stress-strain relationship of saturated sand are explored. Test results show that under drained condition sand specimens with stress history of different type do not change their shear strength for a given mean principal stress. On the other hand, the stress-strain characteristics behaved differently with respect to the stress history. The elastic locus varied with stress history has directional and stress condition effects. Finally, introducing predominant parameters for the difference of the direction and the stress condition between stress history and shear process, as well as taking into account the experimental results, the elastic boundary space due to the stress history is expressed under three dimensional stress conditions.

关 键 词：单调排水剪切 中主应力系数 主应力方向 应力历史 各向异性 应力-应变关系 

分 类 号：TU411[建筑科学—岩土工程]