黏性土包气带中流体迁移规律  

Migration of fluid in the vadose zone of low permeability

作　　者：孙家强[1] 孙超[1] 周睿[1] 赵勇胜[1] 

机构地区：[1]吉林大学环境与资源学院,吉林长春130026

出　　处：《水文地质工程地质》2016年第1期1-5,共5页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目资助(41272256);北京市高校创新能力提升计划项目资助(TJSHG201310772028);环保公益性行业科研项目资助(201409030)

摘　　要：以黏土模拟低渗透包气带环境,探究了混溶流体在包气带中的迁移规律。实验结果表明：混溶流体在横向和垂向的最大迁移距离与流体泄漏量均符合幂函数变化规律y=ax^b。随着流体注入体积的增加,横向和垂向迁移距离不断增大,迁移速率逐渐减小。文章提出以横纵比作为反映流体在包气带中迁移变化规律的重要指标。横纵比总体呈下降趋势,具体分为两个阶段：流体注入体积为0-3 046 m L时,横纵比呈先上升后稳定的趋势,横纵比大于1。此阶段流体以横向发育为主,污染羽剖面呈扁平状椭圆;当流体注入体积大于3 046 m L,横纵比逐渐减小到1以下并持续减小。此阶段流体以垂向发育为主,污染羽剖面逐渐转变为竖直长条状椭圆。This paper explores the migration rules of miscible fluid in the clay vadose zone which is characterized by low permeability. The results show that the largest transversal and vertical migration distances of the miscible fluid are related to leakage volume,and can be expressed as y = ax^b. The transversal and vertical migration distances increase with the injecting fluid,and the migration velocity decrease. In addition,we propose a ratio of transversal to vertical moving distances to reflect the fluid migration rules in the vadose zone. The ratio decreases during a long period,and it can be divided into two stages. Initially,the fluid injection volume increases from 0 to 3 046 m L,the ratio rises and then becomes stable and is always greater than 1. In this stage,the contaminant presents mainly a transversal migration,and the profile of the contaminant plume takes a shape of oblate ellipse. Following this period,the fluid injection volume is over 3 046 m L,and the ratio declines to less than 1 and kept on decreasing. In this stage,the contaminant presents principally a vertical migration,and the profile of the contaminant plume turns to a shape of long ellipse.

关 键 词：包气带 黏土 迁移 横纵比 

分 类 号：P641.2[天文地球—地质矿产勘探]