粘土分散性的判别试验  

Experimental study on clay dispersibility

作　　者：樊恒辉[1] 高明霞[1] 李鹏[1] 吴普特[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院

出　　处：《长安大学学报（自然科学版）》2007年第2期76-80,共5页Journal of Chang’an University(Natural Science Edition)

基　　金：国家863计划重大项目(2002AA2Z4051-2);西北农林科技大学科研专项项目(06ZR41;05ZR42)

摘　　要：针对分散性粘土遇水分散流失的不良性质,应用碎块、针孔、双比重计、孔隙水可溶盐和交换性钠质量分数5种试验方法,研究了西安市黑河水利枢纽工程粘土心墙土料的分散性。研究认为,土料大部分属于非分散性粘土,少部分属于分散性粘土,分散性粘土的蒙脱石与伊利石的质量比值较高;在采用黑河水冲蚀针孔时,分散性粘土有表现为非分散性的趋势;大坝建成后的坝体原状土样属于非分散性粘土。结果表明:蒙脱石与伊利石的质量比值是判别粘土分散性的重要指标,水质对土的分散性具有显著影响;分散性粘土与非分散性粘土合理混合使用可降低粘土的分散性,满足工程要求。The dispersive clay is the clayey soil in which the clay fraction is dispersed and eroded by water so as to the projects be easily wrecked. Based on the poor engineering characteristic of the dispersive clay, this paper studied the dispersity of soil samples for the clay core wall from Heihe hydraulic development project in Xi＇an by double-hydrometer test, pore water salts test, pinhole test, crumb test and exchangeable sodium percent test. It was showed that the most soil samples were dispersive soil and a few were non-dispersive soil, and the values of montmorillonoid and illite relative contents were higher of the dispersive clay than non-dispersive clay. If the river water was chosen as the scouring water in pinhole test, the dispersive clay has the tendency to the non-dispersive clay. After the dam was completed, the undisturbed soil samples from the dam were non-dispersive by some experiments. The results indicate that the value of montmorillonoid and illite relative contents is the important indices for identification, the water quality can obviously effect and improve the soil dispersity, and the dispersity of dispersive soil can be reduced if the non-dispersive soil is reasonably mixed with it, so it can satisfy the requirement of the projects by this method. 4 tabs, 11 refs.

关 键 词：土力学 原状土 分散性粘土 物理化学性质 粘土矿物 鉴定方法 

分 类 号：TU43[建筑科学—岩土工程]