三维高密度电阻率E-SCAN法有限元模拟异常特征研究  

A study on FEM modeling of anomalies of 3-D high-density E-SCAN resistivity survey

作　　者：黄俊革[1] 王家林[1] 阮百尧[2] 

机构地区：[1]同济大学海洋与地球科学学院,上海200092 [2]桂林工学院资源与环境工程系,桂林541004

出　　处：《地球物理学报》2006年第4期1206-1214,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40064001);上海博士后基金资助项目(05R214143)

摘　　要：工程电法勘探中,常需要探测埋深不大、规模较小、分布复杂的目标体,对探测方法的精度要求较高.由于三维高密度电阻率法数据采集密度大,可对目标体进行多方位观测,是目前工程探测中常用的方法之一.本文对三维高密度电阻率E-SCAN法的视电阻率异常特征进行研究.设计几种典型地质体模型,利用有限单元法进行正演计算,并分析其异常特征和分布规律.算例结果表明,E-SCAN法对低阻体的分辨能力强于高阻体.无需对所有电极进行扫描供电观测,即可分辨地质体电性特征及水平位置,但观测结果难以分辨地质体纵向延伸.Geological bodies of small buried depths, small sizes, and complex distribution are often needed to be explored in engineering electric prospecting. Higher accuracy of detective methods is required. Using the 3-D high-density resistivity method, which is one of the normal methods in engineering prospecting, we can get plenty of data and detect the bodies in many bearings. A study of anomaly features in 3-D high-density E-SCAN resistivity survey is done in this paper. Several classical models are designed and calculated using the finite element method to study their anomalous features. The results show that, the resolving power of E-SCAN on low resistivity bodies is stronger than on high resistivity bodies. It dispenses with setting power on all electrodes and can distinguish geologic body＇ s electrical properties and positions. But it is difficult to identify the downward extention of geological bodies by the measurements.

关 键 词：三维 高密度 电阻率 E-SCAN法 视电阻率异常 

分 类 号：P631[天文地球—地质矿产勘探]