不同应力水平下湖相软土流变特性研究  

STUDY OF RHEOLOGICAL PROPERTIES OF THE LACUSTRINE SOFT SOIL UNDER DIFFERENT STRESS LEVEL

作　　者：邓宗伟[1] 朱志祥[2] 曾向军[1] 孔纲强[1] 

机构地区：[1]湖南城市学院土木工程学院,湖南益阳413000 [2]中南大学土木建筑学院,长沙4100753

出　　处：《工业建筑》2014年第6期67-72,共6页Industrial Construction

基　　金：湖南省教育厅重点研究项目(09A016);湖南省科技计划项目(2011FJ3255;2013GK3086);湖南省教育厅一般项目(13C119)

摘　　要：为探明湖相软土在不同应力水平下的流变特性,以洞庭湖区软土为研究对象,进行室内一维固结流变试验,建立了在侧限条件下的流变本构模型,并根据拟合的流变本构模型推导了一维固结情况下的解析解。结果表明:洞庭湖软土具有明显的非线性蠕变特征,当应力水平低于某应力阈值时,软土的流变特性服从Schiffman模型规律,软土固结速度较慢;当应力水平高于某应力阈值时,软土的流变特性服从西原模型规律,软土固结速度较快,并且固结速度随着应力阈值的增加而加快。因此,对湖相软土地区的工程建设,应根据软土的工程性质与所施加的荷载水平而采用不同的沉降计算方法与工程处理措施。In order to understand the rheological properties of lacustrine soft soil at different stress levels , a one-dimensional indoor consolidation creep test was carried out on soft soil in the Dongting Lake area .A rheological constitutive model under lateral confinement conditions was then constructed , and the analytical solution was obtained under one-dimensional consolidation conditions according to the fitted rheological constitutive model .The results indicate that soft soil in the Dongting Lake area has obvious nonlinear creep characteristics .When the stress level is lower than a certain stress threshold , the rheological properties of soft soil follow the rules of the Schiffman model , and the consolidation rate of the soil is low .When the stress level is higher than a certain stress threshold , the rheological properties of soft soil follow the rules of the Nishihara model , and the consolidation rate of the soil is high . In addition, the consolidation rate increases with the increase of the stress threshold .Therefore, in the engineering construction phase of a lacustrine soft soil area , different settlement formulas and engineering treatment measures should be adopted according to the engineering properties of the soft soil and the applied load .

关 键 词：湖相软土 应力水平 流变特性 解析解 

分 类 号：TU447[建筑科学—岩土工程]