卸载作用下淤泥质黏土流变规律试验研究  

Experimental study on rheological property of muddy clay under unloading

作　　者：付艳斌[1] 宋博通[1] 朱合华[2] 

机构地区：[1]深圳大学土木工程学院,深圳518060 [2]同济大学地下建筑与工程系,上海200092

出　　处：《深圳大学学报（理工版）》2009年第4期400-404,共5页Journal of Shenzhen University(Science and Engineering)

基　　金：国家高新技术研究发展计划资助项目(2006AA11Z102);深圳市科技计划资助项目(SY200806270077A)

摘　　要：利用常规压缩仪对上海饱和淤泥质软土进行一维分级卸载实验,得到淤泥质黏土在卸载作用下的应力应变关系,及回弹变形与回弹模量的时效性规律.试验结果表明,回弹变形与卸载比近似呈线性关系;土样在卸载瞬间,回弹速率最大,其后随时间迅速衰减;回弹模量随时间近似呈指数衰减,可用指数方程进行归一化拟合;卸载后的回弹模量远大于压缩模量,其最小比值介于2～7之间.One-dimensional unloading tests were carried out on saturated muddy clay samples from Shanghai by means of routine compressometer. Stress-strain relationship and time-dependency properties of rebound deformation and rebound modulus of muddy clay samples were obtained. The results show that rebound deformation is approximately linear related to unload ratio. Rebound speed reaches the maximum when soil sample is unloaded, and then it decreases quickly with time. The change of rebound modulus with time is normalized to fit with an exponential equation. Rebound modulus much greater than compressive modulus, and the retios under differcst unloading are of the range between 2 and 7.

关 键 词：卸载土体 饱和淤泥质软土 基坑开挖 回弹模量 压缩模量 

分 类 号：TU528.041[建筑科学—建筑技术科学] TU528.044