孔—巷瞬变电磁隧道不良地质体超前预报方法研究  

Seismic prediction of unfavorable geobodies in tunnels using theborehole-roadway transient electromagnetic method

作　　者：李贺 李貅[4] 戚志鹏[4] 曹华科 LI He;LI Xiu;QI Zhi-Peng;CAO Hua-Ke(Key Laboratory of Intelligent Detection and Equipment for Underground Space of Beijing-Tianjin-Hebei Urban Agglomeration,Ministry of Natural Resources,Shijiazhuang 050031,China;Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang 050031,China;College of Earth Sciences,Hebei GEO University,Shijiazhuang 050031,China;School of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China)

机构地区：[1]京津冀城市群地下空间智能探测与装备重点实验室,河北石家庄050031 [2]河北省战略性关键矿产资源重点实验室,河北石家庄050031 [3]河北地质大学地球科学学院,河北石家庄050031 [4]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《物探与化探》2024年第5期1215-1222,共8页Geophysical and Geochemical Exploration

基　　金：河北省引进留学人员资助项目(C20230368);河北地质大学预研项目(KY2024QN28)。

摘　　要：在复杂环境下进行隧道施工,需要解决对溶洞、裂隙等小规模不良地质体的精细探测。为此设计了掌子面前方存在小规模溶洞的隧道施工模型,在掌子面中心点向隧道施工方向打一个钻孔,将电性源放入孔中进行激发,在掌子面上进行阵列式数据采集,采用时域有限元方法对模型进行瞬变电磁三维正演计算。结果表明可以通过源的移动对目标体进行电磁测深,通过掌子面上电磁场分布规律确定不良地质体的平面位置。采用孔中电性源激发的方式,可以提高瞬变电磁对小规模溶洞的探测能力,为隧道环境中提高超前预报精度提供一种可行性手段。Tunnel detection in complex environments requires fine-scale detection of small unfavorable geobodies like karst caves and fissures.Hence,this study designed a tunnel construction model with a small karst cave in front of the tunnel face.A borehole was drilled at the center point of the tunnel face towards the construction direction,and then an electrical source was put into the borehole for excitation.Array data acquisition was conducted on the tunnel face.The 3D forward modeling based on transient electromagnetic data was performed using the time-domain finite element method.As indicated by the results,the electromagnetic sounding of the target was achieved through the movement of the electrical source,and the planar position of the unfavorable geobody was determined based on the distribution patterns of the electromagnetic field on the tunnel face.Therefore,electrical source excitation in a borehole can enhance the detection ability of the transient electromagnetic method on small karst caves,serving as a feasible method for improving the accuracy of tunnel seismic prediction.

关 键 词：瞬变电磁法 隧道超前预报 精细探测 含水溶洞 孔中电性源 

分 类 号：P631.1[天文地球—地质矿产勘探]