西藏山南地区水库松散坝基渗透变形试验及机理研究  

Test and mechanism of seepage deformation for the looses dam foundation in the Shannan region of Tibet

作　　者：李识博[1,2] 王常明[2] 邹婷婷 王钢城[2] 马建全[1] 

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054 [2]吉林大学建设工程学院,吉林长春130026 [3]中国市政工程东北设计研究总院,吉林长春130021

出　　处：《水文地质工程地质》2016年第1期57-63,93,共8页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目资助(41072191);陕西省教育厅科学研究计划项目资助(14JK1464)

摘　　要：对选自西藏山南地区高山宽谷河流区松散坝基土体进行室内渗透变形试验研究,设置不同级配定水头高度及相同级配变水头高度的3组对比试验方案。分析试验中水力梯度及渗透系数的变化情况,将松散坝基渗透试验过程分为颗粒调整、渗流稳定、渗流变化三个阶段。根据试验现象,结合以往渗透变形模式研究,将渗透变形划分为三类:渗透压密、渗透破坏及渗透淤堵。结合渗透变形的力学特征,对这三类渗透变形机理进行分析,并对单个土颗粒受力分析,得出在渗透压密、渗透破坏及渗透淤堵过程中运动颗粒的受力情况。试验结果表明添加淤堵材料有助于减缓、减小基部掏蚀的发生、发展,为该类松散坝基防渗减渗工作提供理论依据。An indoor seepage deformation test was conducted on the loose deposit soil which was taken from the mountains-gully rivers of the Tibet Plateau. During the test,fluid velocity and coefficient of permeability of the specimen were monitored under the three conditions,for instance,the different gradations but the same water head and the same gradations but changes in water head. According to the monitoring results of fluid velocity and coefficient of permeability,the loose dam foundation permeability test can be divided into three sections：particle adjustment section,seepage stabilization section and seepage variation section. Combining with the phenomena during the test and the previous researches,the seepage deformation can be divided into three types： seepage compaction,seepage failure and infiltration clogging. Based on the mechanical characteristics of seepage deformation,the mechanism of the three types of seepage deformation was analyzed. The force condition of an individual soil particle under these three types was analyzed. The test results show that adding clogging material can slowdown or reduce the occurrence and development of basal sapping,which can provide a theoretical basis for the work of infiltration prevention and reduction on loose dam foundation.

关 键 词：松散坝基 渗透变形 渗透压密 基部掏蚀 渗透淤堵 

分 类 号：TV139.14[水利工程—水力学及河流动力学]