文家沟水库筑坝土料分散性和抗渗性能试验  

Dispersivity and impermeability of dam soil in Wenjiagou Reservoir

作　　者：樊恒辉[1,2] 孔令伟[1] 郭敏霞[2] 李鹏[2] 刘惹梅[2] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《岩土工程学报》2009年第3期458-463,共6页Chinese Journal of Geotechnical Engineering

基　　金：科技支撑计划“坡面降雨径流调控与高效利用技术”(2006BAD09B01)

摘　　要：遇水分散并流失破坏是分散性土的重要特征,对工程的安全性造成严重威胁,但是由于分散性土发现较晚,工程实例较少,因而对分散性土的判别方法、分散机理及其应用等研究不够深入。在分析土样物理化学性质和矿物成分的基础上,应用碎块、针孔、双比重计、孔隙水可溶盐和交换性钠百分比等试验方法,对文家沟水库筑坝土料的分散性和分散机理进行了研究,并探讨了土样自身抗渗和在反滤料保护条件下的抗渗性能。研究认为,文家沟水库筑坝土料属于过渡性土和分散性土;土样中含有较多的蒙脱石和钠离子以及酸碱度较高是土样产生分散性的主要原因;土样的自身抗渗较差,但是在有反滤料保护条件下具有良好的抗渗性能。结果表明:黏土产生分散性的条件是土样中含有较多的蒙脱石和钠离子以及酸碱度呈强碱性,分散性土在合适的反滤料条件下具有较强的抗渗性。The key character of dispersive clay is to be dispersed and wrecked by water flows, causing serious threats to engineering safety. But those studies on dispersive clay, such as the methods of identification, dispersive mechanism and their applications, are still not deep enough and satisfactory due to their trivial discovery and few engineering practices. Based on the analysis of physical and chemical characters and mineralogical composition, the dispersivity and dispersive mechanism of the dam soil samples in Wenjiagou Reservoir are studied by double-hydrometer tests, pore water salts tests, pinhole tests, crumb tests and exchangeable sodium percentage tests, and further investigations on the impermeability of soil samples are also carried out by itself and under the protection of inverted filter materials. The results show that soil samples are transitional and dispersive soil because of rich montmorillonoid, plenty of sodium-ion and strong alkalescence. The soil samples have weak self-impermeability, but favorable impermeability under the protection of the inverted filter materials. The studies indicate that soil becomes dispersive clay only under the conditions of rich montmorillonoid contents, more sodium-ion and strong alkalescence, and the dispersive clay presents a better seepage prevention under the protection of appropriate inverted filter materials.

关 键 词：水工材料 分散性土 物理化学性质 分散机理 抗渗性能 

分 类 号：TV443[水利工程—水工结构工程]