扭剪作用下饱和软黏土轴向纯压循环变形及模量软化特性试验研究  

Experimental study on one-way cyclic deformation and softening behavior of saturated soft clay under principal stress rotation

作　　者：王钰轲 黎冰[2] Wang Yuke;Li Bing(College of Water Conservancy and Environmental Engineering, Zhengzhou University, Zhengzhou 450001, China;College of Civil Engineering, Southeast University, Nanjing 210096, China)

机构地区：[1]郑州大学水利与环境学院,郑州450001 [2]东南大学土木工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2019年第5期981-988,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家重点研发计划资助项目(2017YFC1501204);国家自然科学基金资助项目(51578145)

摘　　要：为了研究主应力轴连续旋转下软黏土的轴向纯压循环变形特性,基于空心圆柱扭剪仪(HCA)模拟了交通等类似荷载作用下的圆形应力路径,开展了不同围压和不同循环应力比(CSR)下循环次数达5000次的主应力轴连续旋转试验.研究了饱和软黏土试样的应变累积、应力应变滞回曲线、模量软化等特性,得到了不同循环应力比和不同围压条件下主应力轴连续旋转引起的变形规律.试验结果表明:随着循环次数的不断增加,土体的应力应变滞回曲线有明显的差异,土体剪切模量不断降低.相同有效围压时,随着循环应力比的增大,土体的软化指数逐渐减小;相同循环应力比时,随着有效围压的增大,试样受到的侧向约束增大,土体的软化指数减小.To study one-way cyclic deformation behavior of soft marine clay under principal stress rotation, the circle stress path under traffic and similar loads was simulated based on hollow cylinder apparatus (HCA), and a series of continuous principal stress rotation tests with cycles up to 5 000 times under different confining pressures and different cyclic stress ratios (CSRs) were carried out. The characteristics of strain accumulation, stress-strain hysteretic loop and modulus softening of saturated soft clay samples were studied, and the deformation law caused by continuous principal stress rotation under different CSRs and confining pressures was obtained. Experimental results show that with the increase of the number of cycles, the shear stress-strain hysteresis curves of soil are obviously different, and the shear modulus of soil decreases. With the same effective confining pressure, the softening index of soil decreases gradually with the increase of CSR. With the same CSR, the lateral constraint on the samples increases and the softening index of soil decreases with the increase of effective confining pressure.

关 键 词：原状软黏土 变形 软化特性 主应力轴旋转 

分 类 号：TU411[建筑科学—岩土工程]