震后土体抗剪强度参数试验研究

摘要

In order to accurately evaluate the shear strength parameters for the soil under certain depth after earthquake,the verti-cally loaded multilayer shear model box was developed,which was based on the existing multilayer shear box.It can overcome the defects that the multilayer shear box cannot be loaded at the top.The shear strength parameters and the change of shear strength are evaluated under the action of different peak acceleration of seismic wave by the Shaking table test using the newly developed shear model box.The results showed that:1)with the increase of the peak value of acceleration,the cohesive force decreases but the internal friction angle almost remain constant.2)With the increase of peak value of acceleration,the shear strength of the soil decreases significantly.3)With the increase of the peak value of acceleration,the shear stress level of soil is relatively lower after entering the strain hardening stage.%为了精确模拟不同峰值加速度作用下埋置于一定深度的土体的动力响应，在多层剪切箱基础上研发顶部加载剪切模型箱装置，以弥补多层剪切土箱顶部自由不能加载的缺陷，并结合振动台试验，在室内研究不同加速度峰值的地震波作用下埋置于一定的深度的土地的抗剪强度参数变化及对土体抗剪强度的影响。结果表明：随着加速度峰值的增大，黏聚力不断减小，内摩擦角变化不大；随着峰值加速度的增大，土体的抗剪强度明显降低；随着加速度峰值的增大，土体进入应变硬化阶段所对应的剪应力水平相对降低。