铁路隧道水热害不良地质体大地电磁场特征研究--以川藏铁路茶洛隧道为例  

Magnetotelluric characteristics of hazardous hydrothermal geological structures at railway tunnels-A case study of Chaluo Tunnel of Sichuan-Tibet Railway

作　　者：王维强 宋洪伟 尚铭森[1,2] 母海东 闫丰录[1,2] WANG Weiqiang;SONG Hongwei;SHANG Mingsen;MU Haidong;YAN Fenglu(Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development,Ministry of Natural Resources,Shijiazhuang Hebei 050061,China;Institute of Hydrology and Environmental Geology,CAGS,Shijiazhuang Hebei 050061,China)

机构地区：[1]自然资源部地热与干热岩勘查开发技术创新中心,河北石家庄050061 [2]中国地质科学院水文地质环境地质研究所,河北石家庄050061

出　　处：《钻探工程》2021年第5期9-17,共9页Drilling Engineering

基　　金：中国地质调查局地质调查项目“全国大地热流值测量与靶区优选”(编号:DD20190128)。

摘　　要：以川藏铁路茶洛隧道水热不良地质体大地电磁场特征为研究对象,利用大地电磁测深多测点-多频点阻抗张量成像分析,分解出电性主轴统计玫瑰图、频率分布云图、测点分布云图及构造维性参数等进行大地线性构造识别,利用精细二维反演技术推测地质结构特征,对不良地质体进行成像,为川藏铁路隧道选线提供地球物理参考。得出结论为:拟建隧道处大地构造二维性强,适宜开展二维大地电磁测深作为隧道水热勘察手段;通过查明研究区构造特征,推测出了研究区热泉群深部地热运移模式机理,且该热害影响茶洛隧道建设的可能性很小,只有在杂马岗-毛垭坝断裂与隧道位置交汇处存在一定规模的水害影响。Taking the magnetotelluric behavior of the adverse hydrothermal geological structures at Chaluo Tunnel of Sichuan-Tibet Railway as the research object,and with magnetotelluric multi‑psite,multi‑frequency tensor decomposition,this paper distinguishes the statistical rose diagram of the geo‑electrical strike,frequency‑based cloud maps,site‑based cloud images and structural dimension parameters,and then uses fine two‑dimensional inversion technology to infer the geological structure characteristics,and to image the adverse geo‑structures.The purpose of geostructure imaging is to provide geophysical reference for route selection for the Sichuan-Tibet Railway tunnel.The conclusions are as follows:the Geotectonics at the proposed tunnel is of strong two‑dimensional nature;therefore,it is suitable to carry out two‑dimensional magnetotelluric sounding as a means of tunnel hydrothermal investigation.With characterization of the geo‑structure in the study area,the mechanism of the deep geothermal migration mode of the hot spring group in the study area is deduced,while the possibility of the thermal hazard affecting the construction of Chaluo Tunnel is very small,with only some potential water damage in the position where the fault of Zamagang‑Maoyaba passes through the tunnel.

关 键 词：隧道 大地电磁 阻抗张量成像 二维反演 热害 水害 川藏铁路 

分 类 号：P631[天文地球—地质矿产勘探] U452.1[天文地球—地质学]