用电导率测定自由膨胀率的方法研究  

Correlative researches on free swelling ratio and electrical conductivity of expansive soil

作　　者：龚壁卫[1] 鞠佳伟[1] 叶艳雀[1] 

机构地区：[1]长江科学院,水利部岩土力学与工程重点实验室,湖北武汉430010

出　　处：《岩土工程学报》2011年第8期1280-1283,共4页Chinese Journal of Geotechnical Engineering

基　　金：国家“十一五”科技支撑计划“膨胀土地段渠道破坏机理及处理技术研究”课题(2006BAB04A10)

摘　　要：自由膨胀率是膨胀土分类判别的重要指标之一,室内自由膨胀率试验周期长、影响因素多,试验成果重复性较差。自由膨胀率和土壤电导率均与土壤的阳离子交换量、比表面积密切相关,在土壤的含水率一定的条件下,电导率是一个相对稳定的指标。因此,探索用电导率测定膨胀土的自由膨胀率可以解决自由膨胀率试验困难的问题。采用制备一定含水率条件下的膨胀土样测试了其电导率和自由膨胀率,试验成果表明:土壤电导率的量级可以用来反映膨胀土的膨胀等级。用特定含水率条件下膨胀土样的电导率可以推求土样的自由膨胀率。该成果对于研究采用电导率判别膨胀土的膨胀等级具有重要的实用意义。Free swelling ratio is one of the most important indicators for the expensive soils.The laboratory test for the free swelling ratio needs a long period and has many influencing factors for the outcome.Besides,the test reproducibility is poor.The free swelling ratio and soil conductivity are both closely related to the soil cation exchange capacity and specific surface area.But when the soil moisture content is under certain conditions,the soil conductivity is a relative stability indicator.Therefore,to use the electrical conductivity to measure the free swelling rate of the expansive soil can solve the difficulties in tests for the free swelling rate.Here,certain moisture content is adopted to test the electrical conductivity and free swelling ratio of the expansive soil samples.The test results show that the soil conductivity grades can be used to reflect the expansion level of the expansive soil.Under certain moisture content,their free swelling ratio can be determined by measuring the electrical conductivity of the expansive soil samples.These achievements are of realistic significance for the researches on applying electrical conductivity to the classification of the swelling and shrinking grades of the expansive soils.

关 键 词：膨胀土 自由膨胀率 电导率 

分 类 号：TU443[建筑科学—岩土工程]