人工制备结构性软黏土直剪流变特性研究  

Study on rheological properties of direct shear of artificially prepared soft clay

作　　者：杨爱武 罗伟韬[1] 郑宇轩 YANG Aiwu;LUO Weitao;ZHENG Yuxuan(School of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;Key Laboratory of Soft Soil Characteristics and Engineering Environment of Tianjin,Tianjin Chengjian University,Tianjin 300384,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]天津城建大学土木工程学院,天津300384 [3]天津市软土特性与工程环境重点实验室,天津300384

出　　处：《自然灾害学报》2021年第4期126-133,共8页Journal of Natural Disasters

基　　金：国家自然科学基金(51978440;42177119);天津市自然科学基金项目(19JCZDJC39700);中央高校基本科研业务费专项资金(2232021A-07)。

摘　　要：目前关于软黏土直剪流变特性的研究考虑结构性影响还很少,且从自然界中取得物质成分接近且含水量一致但结构强度不一致的土体很难。本文以天津滨海软黏土为原料土,通过掺加少量不同含量的水泥制成不同结构强度但含水量相同的软黏土试样。采用LTDZJ-15自动应力应变控制式直剪流变仪,对不同结构性软黏土试样进行室内剪切流变试验,研究不同结构强度影响的软黏土剪切流变特性。试验结果表明:结构性对土体直剪流变特性有明显影响。当剪应力水平较低、小于结构屈服应力的情况下,结构性软黏土的剪切流变曲线均表现为衰减稳定流变;当剪应力水平较高且大于结构屈服应力时,结构性软黏土呈现加速变形破坏状态。当结构强度增大时,其剪切模量增大,剪应变减小且逐渐趋近于零,应变率减小且随着时间增长逐渐趋近于零。研究成果可为工程设计、计算提供理论依据。At present,great achievements have been made in the study of many characteristics of soft clay,but there is still a lack of practical engineering requirements.In this paper,Tianjin Binhai structural soft clay samples with different structural strength but the same water content were prepared by adding a small amount of cement with different content.In addition,LTDZJ-15 automatic stress-strain controlled direct shear rheometer was used to carry out shear rheological tests on different structural soft clay samples,and the effect of shear rheological properties and structural strength on deformation was studied.The test results show that the structure has a significant effect on the rheological properties of soil under direct shear.When the shear stress is lower than the yield stress,the shear rheological curves of structural soft clay are attenuated and stable rheological.When the shear stress is higher than the yield stress,the structural soft clay presents accelerated deformation and failure.When the structural strength increases,the shear modulus of soft clay increases,the shear strain of soft clay decreases and turns between 50~80kPa,and the strain rate of soft clay decreases and gradually approaches zero with the growth of time.The research results can provide theoretical basis for engineering design and calculation and reference for practical engineering.

关 键 词：软黏土 结构强度 剪切流变 剪切模量 变形 

分 类 号：TU447[建筑科学—岩土工程] X14[建筑科学—土工工程]