库水环境变化对分散性土工程性质的影响

Influence of Water Environment on Engineering Properties of Dispersive Clay

以分散性土为研究对象,在土中掺入不同质量分数的盐酸和氢氧化钠模拟库水环境的变化,进行针孔、碎块、压缩、直剪、扫描电镜等试验,分析了库水环境变化对分散性土的分散性、压缩变形特性、抗剪强度以及微观结构特性的影响。结果表明:酸碱对分散性土的分散性、压缩变形特性以及抗剪强度均有显著影响,库水环境中酸碱含量的增加均可抑制土体的分散性;碱性库水环境下分散性土的压缩模量、黏聚力、内摩擦角随着碱含量增大呈现先增后减的变化规律,而酸性库水环境下分散性土的压缩模量、黏聚力和内摩擦角随酸含量的增大而减小。研究结果说明,在碱性库水环境条件下,分散性土坝较为安全,而当库水呈酸性时,需要密切关注分散性土坝的工程性能变化。

A series of laboratory tests w ee performed to investigate the influence of engineering properties of dispersive clay,caused by the change of water environment.The pinhole,crumb,compression,direct shear and SEM tests had been investigated in different contents of hydrochloric acid and sodium hydroxide,so as to study the effect on the dispersity,defor^nation property,strength property and microstructure characteristics of dispersive clay with the change of water environment.The test results show-that the change of water environment has a significant influence to the dispersity,compressibility,strength property and microstructure characteristics of dispersive clay.The dispersity is reduced with the increasing of acid and alkali.The compressibility,cohesion and internal frictional angle are climbed up and then declined with the increasing of alkali while reduced with the increasing of acid.The dispersive dam is safe in alkaline water environment.But it needs pay attention to engineering properties while in acidic water environment(such as acid rain).