循环荷载作用下软黏土变形特性试验研究

Experimental Study on Deformation Characteristics of Soft Clay Under Cyclic Loading

为保证轨道交通沿线建筑和住房工程的安全稳定,对循环荷载作用下软黏土的变形特点开展研究。通过对软黏土进行应力控制的室内循环三轴试验,研究了部分排水条件下循环荷载作用饱和软黏土的累积轴向应变发展规律,分析了循环应力比和振次影响。试验结果表明:不同循环应力比条件下,累积轴向应变在试验初始阶段快速增长,随振次的增大逐渐平稳并达到一稳定值;在此基础上,提出了考虑循环应力比和振次影响的饱和软黏土累积轴向应变计算模型,并对比分析了三种累积轴向应变计算模型的计算结果,结果表明模型3对累积轴向应变具有较好的预测能力。

The accumulated axial strain behavior of the saturated clay under the cyclic loading in partially drained conditions is analyzed.Among that,the effects of the cyclic stress ratio,and number of cycles are investigated.The test results show that the accumulated axial strain increases rapidly at the initial stage of the test,and then reaches a stable value with the increase of number of cycles under different cyclic stress ratios.Based on that,an empirical model to predict the accumulated axial strain of the saturated soft clay(Model 3)considering the effects of the cyclic stress ratio and the number of cycles is proposed,and the evaluation results of the three empirical models for the accumulated axial strain are compared and analyzed.The results show that Model 3 has a good prediction capability for the accumulated axial strain.