考虑含砂量影响的砂-黏混合土应力-应变关系特性研究.pdf

Journal of Engineering Geology工程地质学报1004-9665/2014/22(6)-1102-07
DOI:10.13544/j.cnki.jeg,2014.06.013
考虑含砂量影响的砂-黏混合土应力-应变关系特性研究
贾卫兵①郭
杨爱武
(①天津城大岩土工程技术有限公司天津300384)
(②天津城建大学天津市软土特性与工程环境重点实验室天津300384)
摘要将砂与黏土按不同比例干重量均匀混合制成砂一黏混合土,进行不排水三轴剪切试验,研究了含砂量和试验圃压对
混合土初始切线模量和应力-应变关系的影响,并对其作用机理进行了分析。研究结果表明:含砂量小于50%时、可以认为混
合上初始切线模量与含砂量无关。含砂量大予50%小于80%时,初始切线模量随含砂量增加呈线性趋势增长。通过把含砂量
参数引入到初始切线模量中对 Duncan- Chang模型进行修正,使修正后的模型能够描述含砂量小于80%时混合土的应力应变
关系。当含砂量超过80%,混合土呈应变软化型,随含砂量的增加,初始切线模量逐渐保持稳定,应力-应变曲线峰值应变左
移,可应用软化模型对其应力-应变关系进行描述。围压对混合土应力-应变关系有很大影响,在双对数坐标中,随试验围压的
增大,初始切线模量呈线性趋势增长。
关键词砂一黏混合土初始切线模量应力-应变关系邓肯一张模型软化模型
中图分类号:P642.131文献标识码:A
STRESS-STRAIN RELATIONSHIPS OF SAND-CLAY MIXTURES WITH
DIFFERENT SAND CONTENTS
JIA Weibing GUO Feia YANG Aiw ao
(Oianjin Chengda Geotechical Engineering Technology Co, Ld, Tianjin 300384
(Key Iaboratory ofsof Soil Engineering Character and Engineering Enuironment of Tianjin, ianjin Chengjian University
Tianjin 300384)
Abstract The sand-clay mixtures are made by mixing sand and marine clay with different dry weight proportions
homogeneously. Undrained triaxial tests are conducted to study the effects of sand content variation and confining
pressure on the initial shear modulus and stress-strain relationships of the mixtures. Mechanisms are analyzed. Tests
results show that there is no obvious relationship between the initial shear modulus and the sand content variation
when sand content is less than 50% For sand-clay mixtures with sand content ranging from 50% to%, the initial
shear modulus increases linearly with the rowing and content. The sand content parameter should be introduced
into the initial shear modulus so that the modified Duncan-chang model can be used to imitate the stress-strain
relationships of the sand-clay mixtures with sand content less than 80%effectively. When the sand percentage is over
than 80%, the characteristic of strain softening occurs. The initial shear modulus is kept steady gradually. The peak
strain becomes smaller. The softening model is useful to describe the stress-strain relationships of sand-clay mixtures
收稿日期:2013-09-11;收到修改稿日期:2014-01-02.
基金项目:国家白然科学基金项日(511791864137291)资助
第一作者简介:贾卫兵(1981-),男,工程师,主要从事土动力学方面的研究.Email:Tory_yy9126.com