利用最大面积收缩率对膨胀土进行判别与分类的试验研究  

Experimental Study on Identification and Classification of Expansive Soil Using Maximum Area Shrinkage-cracking Ratio

作　　者：韩少阳 王保田[1,2] HAN Shaoyang;WANG Baotian(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;Jiangsu Research Center for Geotechnical Engineering Technology,Hohai University,Nanjing,Jiangsu 210098,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学江苏省岩土工程技术工程研究中心,江苏南京210098

出　　处：《河北工程大学学报（自然科学版）》2021年第3期7-12,共6页Journal of Hebei University of Engineering:Natural Science Edition

基　　金：江苏省普通高校学术学位研究生科研创新计划项目(KYZZ16_0270);中央高校基本业务经费资助项目(2017B647X14);国家自然科学基金资助项目(51778211)。

摘　　要：提出一种对膨胀土进行判别和分类的新指标——最大面积收缩率(SCR),其定义为最大面积收缩率试验中试样干燥后收缩裂隙的总面积与试样初始面积的比值。通过对不同地区土样开展试验,研究了制样初始含水率、初始厚度、接触面粗糙度以及环境温度对试验结果的影响,并对SCR作为膨胀土判别与分类指标的可信度与可靠度进行了分析,最终提出了利用SCR对膨胀土进行分类的界限指标。试验结果表明:初始含水率和界面粗糙度对SCR用于膨胀土的判别和分类没有影响;当初始厚度限制在8 mm以内时,可以忽略厚度对试验结果的影响;建议烘干温度为105℃。SCR与蒙脱石含量、阳离子交换量线性相关,能较好地反应膨胀土的胀缩特性;SCR与标准吸湿含水率和塑性指数线性相关,体现出利用SCR对膨胀土进行判别与分类具有较高的可信度。最大面积收缩率试验操作简单、周期短且可重复性高。An index parameter called the maximum area shrinkage-cracking ratio(SCR)was proposed in this paper.It was defined as the ratio of the total area of shrinkage cracks of soil after drying to the initial surface area of the soil sample in a standardized mold.The effect of four factors namely,initial water content,initial sample thickness,mold surface roughness and test temperature were investigated using the soil samples from many different regions.After that,the reliability of using SCR to classify expansive soil was analyzed.Finally,the classification of expansive soil by SCR is proposed.The test results show that the initial water content and mold roughness have little influence on the identification and classification.When the sample initial thickness is limited to 8 mm,the influence can be ignored.The recommended drying temperature is 105℃.Besides,SCR is linearly correlated with the montmorillonite content and cation exchange capacity,which can reflect the nature of expansive soil;The linear correlations between SCR and standard moisture absorption water content and plasticity index indicate that it is highly reliable to identify and classify expansive soil using SCR.The maximum area shrinkage-cracking ratio test is simple and credible.

关 键 词：膨胀土 最大面积收缩率 判别及分类 

分 类 号：TU44[建筑科学—岩土工程]