黏性土渗透性温度效应实验研究  

LABORATORY TESTS FOR TEMPERATURE EFFECTS OF CLAYEY SOIL PERMEABILITY

作　　者：王媛[1] 施斌[1] 高磊[1] 刘瑾[1] 

机构地区：[1]南京大学地球科学与工程学院地球环境计算工程研究所,南京210093

出　　处：《工程地质学报》2010年第3期351-356,共6页Journal of Engineering Geology

基　　金：国家自然科学基金重点项目资助(No.40730739)

摘　　要：由于全球气候变暖、城市热岛效应加剧和核废料地质处置等原因,温度对黏性土工程性质的影响日益受到关注。本文在实验的基础上,采用直接测量法,对南京下蜀土、淤泥质土以及混合土3种试样,进行了5°～45°温度下的变水头渗透实验,分析了温度对黏性土渗透性的影响。实验结果表明:温度对3种试样的渗透性均有较大影响。温度越高,渗透性越大;试样的密度越大,渗透系数随温度变化率越低;在3种试样中,混合土的渗透系数高于淤泥质土和下蜀土的对应值,而淤泥质土的渗透系数又略大于下蜀土。最后对黏性土渗透性的温度效应机理进行了分析,认为水的动力黏滞性,黏粒的双电层厚度以及土的微结构三方面因素的共同作用引起了黏性土渗透性的温度效应。Due to many reasons such as the global warming,urban heat island effect and the geological concerns of nuclear waste disposal,temperature effects on the engineering properties of the clayey soils have being paid more and more attention.This paper uses the falling head permeability test to measure the permeability of clayey soils directly at various temperatures from 5 to 45℃.The soil samples are made from Nanjing Xiashu soil and silt clay.The results show that the temperature has significant impact on the permeability of the soil specimens.Firstly,the permeability increases upon heating;secondly,as the dry density of the clayey soil increases,the variation of permeability with temperature decreases correspondingly;thirdly,the mixed soil shows greater permeability than either silt clay or Nanjing Xiashu soil,and the silt clay＇s permeability is a bit higher than that of Nanjing Xiashu soil within the experimental temperature range from 5 to 45℃.Finally,the mechanism of temperature effects on the permeability of clayey soils is discussed in terms of the viscosity of water,the double layer and micro-meso structure change with temperature.

关 键 词：黏性土 渗透系数 温度效应 机理 

分 类 号：P642.13[天文地球—工程地质学]