中粗砂改良膨胀土的收缩性试验研究  

Study on Shrinkage Test of Medium-coarse Sand Treated Expansive Soil

作　　者：易志斌 YI Zhibin(Hunan Yiyang-Loudi Expressway Construction and Development Company Ltd.,Yiyang 413000,Hunan,China)

机构地区：[1]湖南省益娄高速公路建设开发有限公司,湖南益阳413000

出　　处：《路基工程》2018年第5期144-148,共5页Subgrade Engineering

基　　金：湖南省交通科技计划项目(200944)

摘　　要：以膨胀土的收缩性指标为研究对象,探讨工程中利用中粗砂作为膨胀土物理改良材料的可行性。通过对膨胀土掺加不同比例的中粗砂开展收缩试验,分析了中粗砂改良膨胀土的线缩率、体缩率、缩限和收缩系数等4个收缩性指标的变化规律。结果表明:随着中粗砂掺量增加,线缩率、体缩率和收缩系数等3个指标呈一元三次函数关系逐渐减小,当中粗砂掺量不大于10%时变化幅度较大,掺量大于10%时变化幅度较小。缩限随中粗砂掺量增加呈一元四次函数关系变化,当中粗砂掺量不大于10%时缩限随中粗砂掺量增加而减小,掺量大于10%时缩限随中粗砂掺量增加而增大。中粗砂最佳掺量为10%~15%。This paper studies shrinkage index of the expansive soil to find out the feasibility to improve the expansive soil with medium-coarse sand in engineering.Add medium-coarse sand with different proportions in the expansive soil,and carry out shrinkage test to study the change rules of the linear shrinkage ratio,volume shrinkage ratio,shrinkage limit and shrinkage coefficient,the 4 shrinkage indexes.The result shows that with the increment of medium-coarse sand,the linear shrinkage ratio,volume shrinkage ratio and shrinkage coefficient decreased gradually in one dimensional cubic function.When the increment of medium-coarse sand less than 10%,the change range is bigger,when more than 10%,the change smaller.With the increment of medium-coarse sand,the shrinkage limit changed in one dollar four times function,When the increment of medium-coarse sand not more than 10%,the shrinkage limit decreased with increment,and if more than 10%,the shrinkage limit increased with the increment.The optimum added quantity is 10%～15%.

关 键 词：膨胀土 中粗砂 改良 收缩性 

分 类 号：TU411.2[建筑科学—岩土工程]