Conductivity characteristics of magmatic rock intrusions contained in metamorphic rock strata in Mupi Highway Tunnel  

木皮公路隧道变质岩地层中含岩浆岩侵入体的电性特征

作　　者：Li Bin Xu Qiang Yu Jianhua Cheng Qiang Feng Chongde Zhao Hu Liu Tianxiang Yang Xubo 李斌;许强;余建华;程强;封崇德;赵虎;刘天翔;杨绪波(成都理工大学地质灾害防护与地质环境保护国家重点实验室,四川成都610059;四川省公路规划勘察设计研究院有限公司,四川成都610041)

机构地区：[1]Chengdu University of Technology,State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Sichuan,Chengdu 610059,China [2]Sichuan Highway Planning,Survey,Design and Research Institute Ltd.,Sichuan,Chengdu 610041,China

出　　处：《Applied Geophysics》2025年第1期146-160,234,235,共17页应用地球物理(英文版)

基　　金：National Natural Science Foundation of China(41630640);National Science Foundation of Innovation Research Group(41521002);National Natural Science Foundation of China(41790445);Construction S&T Project of Department of Transportation of Sichuan Province(Grant No.2020A01).

摘　　要：The stratum lithology and geological structure of the highway tunnel in the mountainous areas of western China are complex,and the engineering geological conditions are complicated.When the highway tunnel passes through different lithological strata,its structural design and construction technology are completely diff erent.Therefore,in order to support the tunnel design and construction,the tunnel survey Among them,the identification of the contact boundary between magmatic rock and metamorphic rock and the grade of surrounding rock is very important.Through magnetotelluric survey of the Mupi tunnel of Jiuzhaigou-Mianyang highway on G8513 line,2D forward numerical simulation,1D,2D,3D inversion,and engineering geological analysis,it is revealed that the electrical characteristics of each layer,focusing on the identification of the contact boundary between magmatic rock and metamorphic rock.This study provides the electrical characteristics of the magmatic rock and metamorphic rock contact boundary of the Mupi Tunnel.It is speculated that the boundary is revealed by the tunnel construction excavation,which verifies the correctness of the geophysical inversion model and provides a more detailed design basis for the tunnel design.I believe that taking the Mupi Tunnel survey as an example,through this research,it can provide detailed geophysical evidence for highway tunnels to distinguish between magmatic rock and metamorphic rock.中国西部山区公路隧道地层岩性及地质构造复杂,工程地质条件复杂,公路隧道在不同岩性地层中通过时,其结构设计及施工工艺都截然不同,故为支撑隧道设计及施工,在隧道勘察中,岩浆岩与变质岩接触界线及围岩等级的判识,至关重要。通过G8513线九寨沟至绵阳高速公路木皮隧道大地电磁法勘探,2维正演数值模拟、1维、2维、3维反演及工程地质分析等方法,揭示了沿隧道设计线位地表至隧道设计标高以内50m深度范围内各地层的电性特征,重点讨论了岩浆岩与变质岩接触界线的判识。本研究提供了木皮隧道的岩浆岩与变质岩接触界线的电性特征,推测界线经隧道施工开挖揭示,验证了物探反演模型的正确性,为隧道设计提供了较为详实的设计依据。相信以木皮隧道勘察为例,通过本研究,可为公路隧道在岩浆岩与变质岩判别时提供详实的地球物理依据,可为公路隧道地质勘察及设计提供强有力的支撑。

关 键 词：Highway tunnel magnetotelluric method engineering geology magmatic rock metamorphic rock 

分 类 号：P61[天文地球—矿床学]