初始主应力方向对饱和粉土循环剪切特性的影响

The Effect of Initial Principal Stress Orientation on the Cyclic Shear Behavior of Saturated Siltehavior of Saturated Silt

摘要:

利用“土工静力 动力液压 三轴扭转多功能剪切仪”，针对采用初始成样含水率为0和10%夯击法制备重塑饱和粉土试样，在初始平均主应力为100 kPa，初始中主应力系数为0.5，初始偏应力比为0.433，初始主应力方向角分别为0°、30°、45°的条件下完成非均等固结，然后保持平均主应力和中主应力系数恒定进行不排水循环扭剪实验。着重探讨初始成样含水率和初始主应力方向对粉土动力剪切变形、强度及孔压变化等特性的影响。实验结果表明：初始主应力方向对重塑粉土的变形与强度特性的影响程度有所不同；初始成样含水率对饱和重塑粉土的动力变形及强度特性具有显著影响。

Abstract:

By using a soil static and dynamic universal triaxial and torsional shear apparatus，stress-controlled undrained cyclic torsional tests were performed on remolded saturated silt prepared by tamping methods with initial sampling water contents of 0% and 10%.The initial anisotropic consolidation conditions included an initial mean principal stress of 100 kPa，an initial intermediate principal stress coefficient of 0.5，an initial deviator stress ratio of 0.433，and principal stress initial orientation angles of 0°，30°，and 45°，respectively.During the undrained cyclic shearing process，the mean principal stress and the intermediate principal stress coefficient were fixed.We studied the effects of the initial orientation of the principal stress and the initial sampling water content on the silt’s dynamic shearing deformation，its strength，and its pore water pressure development.The test results show that the extent of the initial principal stress orientation’s effect on the remolded silt’s deformation and strength behaviors varied，and that the initial sampling water content has considerable influence on the cyclic behavior of saturated remolded silt.