大坝防渗土样物理化学性质及分散性研究  

Study on the dispersibility of physical and chemical properties analysis and dispersive test for soil core wall

作　　者：巨娟丽[1] 严宝文[1] 刘俊民[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《西北农林科技大学学报（自然科学版）》2008年第2期189-193,共5页Journal of Northwest A&F University(Natural Science Edition)

基　　金：陕西省自然科学基础研究计划项目(2005D06)

摘　　要：【目的】了解某大坝防渗心墙土料产生分散性的原因。【方法】对6组土样的物理化学性质进行了测定，并采用双比重计法、针孔试验、碎块试验、孔隙水可溶盐试验和交换性钠百分比试验5项室内判别试验，分别对6组土样的分散性进行鉴定。【结果】6组土样均为低液限粘土，粘粒（〈0．005mm）含量为120～275g／kg，pH值较高，为8．29～9．07，属强碱性土；6组土样易溶盐含量为0．234-0．523g／kg，中溶盐含量为0．33～0．66g／kg，难溶盐含量为11．41～148．79g／kg；6组土样中粘土矿物的主要成分均是伊利石，其含量为130～220g／kg，全土中蒙脱石含量较少（43～87g／kg）。经5项室内判别试验综合判定，2号和4号土样均为过渡性土，其他4组土样均为分散性土。【结论】土样粘粒（〈0．005mm）含量低、pH值高及土样中含有一定量的钠离子，是土样产生分散性的主要原因。[Objective] The study is to find out the dispersive mechanism of core wall. [Method] Six groups of soil samples of physical and chemical properties were determined. The tests for identification of dispersive clay soils were studied by double-hydrometer test,pinhole test,crumb test,test for anion of soluble salts of pore water and test for percentage of exchangeable sodium. [Result] Six groups of soil samples were CL,clay （〈0. 005 mm） content being 120-275 g/kg,with higher soil pH,from 8.29 to 9.07,which belongs to alkaline soil,a strong alkaline soil; six groups of soil samples soluble salt content is 0. 234- 0. 523 g/kg,the dissolved salt content is 0.33-0.66 g/kg,insoluble salt content is 11.41-148, 79 g/kg;6 group of clay minerals in the soil samples that the main ingredients is grundite,and its content is 130-220 g/kg,montmorillonite is little,only 43-87 g/kg. Based on comprehensive judge ment,No. 2 and No. 4 samples are determined to be transition clay and the remaining 4 groups the dispersive clay. [Conclusion] Clay soil samples （〈0. 005 mm） in low,higher pH and soil samples contain a certain amount of sodium are the main reasons for these groups.

关 键 词：土坝 心墙土料 分散性 粘土矿物 

分 类 号：TU41[建筑科学—岩土工程]