干湿循环条件下水泥改性膨胀土变形和强度试验  

Experimental Research Deformation and Shear Strength on Cement-treated Expansive Soil During Wetting-drying Cycles

作　　者：王建磊[1] 王艳巧[2] 杨广栋[2] 张扬帆[2] 姜宏雨 

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《郑州大学学报（工学版）》2016年第4期62-66,共5页Journal of Zhengzhou University（Engineering Science）

基　　金：中央高校基金科研业务费专项基金(2014B36614)

摘　　要：为了探究干湿循环作用对水泥改性膨胀土力学性质的影响,以合肥地铁1号线太湖路车站基坑膨胀土为试验对象,进行了不同水泥掺入比和不同养护龄期的水泥改性膨胀土直剪试验,确定了最佳水泥掺入比以及最佳养护龄期.在此基础上,进行了干湿循环条件下膨胀土和水泥改性膨胀土的胀缩变形试验和直剪试验.试验结果表明:膨胀土的胀缩变形过程并不完全可逆,随干湿循环次数的增多,抗剪强度逐渐减小,绝对胀缩率逐渐增大,并最终趋于稳定;水泥改性后的膨胀土抗剪强度明显提高,水稳性显著提升,胀缩性明显减弱;经水泥改性后,膨胀土受干湿循环作用的影响显著减小.In order to reveal the influence of wetting-drying cycles on the mechanical of cement-treated expan- sive soil, the expansive soil obtained from excavation of Hefei Metro Line 1 Taihu Road Station was taken as test object. The optimal cement ratio and curing period were determined, direct shear test was conducted un- der different cement ratio and curing period cement-treated expansive soil. Based on this, expensive soil and cement-treated expansive soil variation of deformation and strength test was conducted under wetting-drying cy-cles. It was shown that the swelling-shrinkage deformation of expansive soils was not completely reversible. Under wetting-drying cycles, shear strength of expansive soil decreased, the total ratio of swell-shrink increase and stabilized finally. Cement modified expansive soil can improve the shear strength of expansive soil and the swell-shrink of expansive was decline obviously. Variation of cement-treated expansive soil significantly de-creased during wetting-drying cycles.

关 键 词：干湿循环 膨胀土 水泥改性 变形 强度 

分 类 号：TU443[建筑科学—岩土工程]