膨胀土膨胀变形时程特性研究  

Study on Time-Related Characteristics of Expansive Soils Swelling Deformation

作　　者：黄华县 张春顺[2] 

机构地区：[1]广州城建开发南沙房地产有限公司,广东广州511457 [2]中南大学土木建筑学院,湖南长沙410075

出　　处：《湖南工业大学学报》2009年第4期6-10,共5页Journal of Hunan University of Technology

基　　金：湖南省教育厅基金资助重点项目(07A017);湖南省自然科学基金资助项目(08JJ3092)

摘　　要：为研究膨胀土膨胀变形随时间的变化,进行了2组南宁膨胀土室内单向浸水膨胀试验和膨胀土桩基灌溉模拟试验,分别对有荷、无荷膨胀土的线胀率的时程特性和基桩桩周膨胀土变形的时程特性进行了较长时间的研究。研究发现,尽管土样的初始含水量及干密度不同,但土样有荷膨胀变形的时程特性具有相似的规律:有荷(大于50kPa)情况下,土样线胀率lg与时间t曲线可分为3个阶段,且该曲线可以用指数关系进行精准描述;无荷膨胀土膨胀率lg与t的关系用对数函数拟合更为精确;对桩基模拟试验结果进行分析和数值拟合,建立了考虑时间因素的桩周土隆起量的指数函数关系式,为进一步研究桩-土共同作用奠定了试验基础。In order to study the expansive soils deformation over time, carries out two groups of experiments on Nanning expansive soils, which one is indoor 1-D immersion test and the other is foundation irrigation simulation. After a long period investigation on the time-related swelling ratio and the expansive soils deformation around pile base, founds that though soil samples containing different initial moisture and dry densities, the loaded expansive soils appear similar deformation behavior over time. When loaded （ 〉50 kPa ）, the curve of swelling ratio lg δ against time can be generally divided into three stages, which can be accurately described by exponential law in semi-logarithmic coordinates, and for unloaded samples, the relation of lg δ-t can be more precisely fitting with logarithmic function. Then conducts a numerical simulation to analyze the model pile test, establishes an exponential function relation concerning the time-related swelling behavior of the pile side soil, and lays experimental basis for further exploration on interactions between piles and expansive soils.

关 键 词：膨胀土 线胀率 时程特性 变形规律 

分 类 号：TU443[建筑科学—岩土工程]