岩柱中水体入渗过程的高密度电阻率成像法研究  

Study about water infiltration process in rock block using high density electrical resistivity tomography

作　　者：伍开江[1] 周启友[1] 

机构地区：[1]南京大学地球科学系,南京210093

出　　处：《水文地质工程地质》2005年第2期76-81,共6页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目(40371021)

摘　　要：本文应用高密度电阻率成像法探讨了室内实验尺度岩柱中的这一入渗过程。首先建立了电法勘探的电位场数学模型,用有限元法进行了电位场正问题的求解。然后应用基于序列二次规划(SQP)方法的电阻率反演算法,由测量数据反演得到了岩石电阻率在二维空间上的分布。由岩柱中水体入渗过程的电法测量数据反演得到的电阻率图像反映了岩柱中水分的空间变化过程。岩柱中电阻率的空间分布及其随时间的变化表明水体的入渗是不均匀的,在岩柱周边渗流较快,而在中部存在滞后现象。得到的相对电阻率图像也反映了岩柱周边存在的微裂隙。The monitoring of water infiltration process in the porous medium is an important work of hydrology and environmental sciences.In this paper,we investigated the infiltration process in a rock block of laboratorial scale by high density electrical resistivity tomography.First,the corresponding numerical model of the electrical field was constructed.The forward problem of ERT was solved with finite element method.Then,the 2-D electrical resistivity was inversely got from the data of ERT survey using the algorithm based on the sequential quadratic programming (SQP) method.The calculated results represented the spatial variation of water in the rock column.The spatial and temporal variations of electrical resistivity in the rock column show that the infiltration process in the is asymmetric,faster at the near side area of rock column than in the central area.The results also suggest the existence of tiny fractures at the near surface area of the rock block.

关 键 词：高密度电阻率成像法 有限元法 SQP方法 人渗过程 

分 类 号：P631.322[天文地球—地质矿产勘探]