坑道直流电阻率法超前探测研究  

A study on advanced detection using DC resistivity method in tunnel

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5期1529-1538,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40064001);上海博士后基金项目(05R214143);同济大学理科发展基金资助

摘　　要：坑道空腔的存在使其周围电场分布不同于全空间的电场分布．以无限大板状体为例求解全空间电场分布，提出探厚比概念以讨论超前探测极限问题．通过对比全空间与坑道内超前探测异常形态可知，坑道空腔只会影响极距较小时的视电阻率幅值，不会掩盖迎头前方地质体的异常响应．大量模型计算结果表明，电阻率异常极值位置与板状体位置之间的差异在5-10倍之间，且同时受到异常体厚度、电性以及板状体倾角的影响．仅利用电阻率极值位置准确解释超前探测异常的难度较大．The distribution of the electric field around a tunnel is different from that in full space because of the tunnel-cavity effect. Taking the infinite plate for instance, the distribution of electric field in full space is solved and detection-thickness ratio is presented to discuss the limit of advanced detection. The apparent resistivity can be influenced by on small spacing of electrodes, but the anomaly of geologic-bodies ahead of the tunnel is not screened by the tunnel-cavity＇ s effect. The calculating results of many models show that the place of the anomalous extreme is 5 - 10 times the plate and influenced by thickness and electric property of the plate. It is difficult to determine exactly the geologic body only using the place of the anomalous extreme.

关 键 词：坑道 电阻率 探厚比 超前探测 

分 类 号：P631[天文地球—地质矿产勘探]