摘要
由于软黏土渗透系数很小,目前针对饱和软黏土的循环荷载试验绝大多数都是在不排水条件下进行的。但对交通荷载而言,软黏土承受经年累月的长期循环荷载作用,实际的排水条件应该是部分排水的。基于此,通过对温州原状饱和软黏土进行不同循环应力比下的不排水和部分排水大周数(50 000次)循环三轴试验,分析了长期循环荷载作用下排水条件对饱和软黏土动力特性的影响。研究结果表明与不排水条件相比,部分排水条件下软黏土试样的动力特性表现出很大的不同。随着循环次数的增加,部分排水条件下的孔压随先增加后降低,存在一个峰值;经过较大的循环次数后,回弹应变逐渐减小,应力-应变滞回圈逐渐缩短,面积也明显减小。为了准确预测交通荷载作用下的长期沉降,采用部分排水条件进行试验是十分必要的。
Most of the existing cyclic triaxial tests on saturated soft clay were conducted under undrained condition because of the very low permeability of soft clay. But as for traffic loading, the actual drainage condition is partially drained because soft clay is subjected to long-term cyclic loading for a series of years. Triaxial tests with large number of cycles (50 000) are conducted under on natural Wenzhou soft clay undrained and partially drained conditions. Influence of drainage condition on dynamic behavior of saturated soft clay is analyzed. Results show that the dynamic behavior of soft clay under partially drained condition is very different from that under undrained condition. With the increasing number of cycles, the pore water pressure firstly increases and then decreases with a peak value. After a large number of cycles, the resilient strain gradually decreases and the stress-strain hysteresis loops under a single cycle shortens with smaller area. It is indispensable to conducting tests under partially drained condition to predict the long-term settlement under traffic loading.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2013年第S2期94-99,共6页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51025827
No.51109164)
浙江省科技计划项目(No.2010C33076)
广西岩土力学与工程重点实验室资助项目(No.11-KF-08)
关键词
软黏土
不排水
部分排水
长期循环荷载
soft clay
undrained condition
partially drained condition
long-term cyclic loading
