艰险山区阵列式三维音频大地电磁勘探方法与应用

An Array-based 3D Audio-frequency Geophysical Exploration Methodand Its Application in Challenging Mountainous Areas

艰险山区是铁路工程勘探领域的重难点。地球物理方法具有设备轻便、施工效率高、成果直观的特点,适合艰险山区的探测工作。大跨度硐室横向范围宽,单条物探测线难以满足勘探精度要求。为此,本文介绍了适用于艰险山区大跨度硐室勘察的阵列式三维音频大地电磁勘探方法,该方法测线布置综合考虑了隧道埋深、硐室跨度,以及测点分布均匀性和边缘效应对探测精度的影响,有效提高了外业资料质量,通过联合反演构建了详实的地下三维视电阻率数据体,可直观反映地下地质体异常空间展布情况。研究成果有效揭示了破碎富水岩体地下空间赋存形态,为隧道施工设计提供了参考。

Exploration in challenging mountainous areas,as recognized for its significant difficulty,is always taken as an important subject in railway engineering.Geophysical methods,characterized by portability,high operational efficiency,and intuitive data representation,are applicable to investigations in such difficult terrains.Largespan chambers,with their extensive lateral extents,cannot be adequately surveyed by a single geophysical profile line,demanding higher precision approaches.This paper presented an array-based 3D audio-frequency magnetotelluric exploration method tailored for investigating large-span chambers in challenging mountainous areas.The profile line layout comprehensively considers tunnel depth,chamber span,uniformity of measurement point distribution,and the impact of edge effects on exploration accuracy,thereby significantly enhancing the quality of field data.Through joint inversion,a detailed 3D apparent resistivity database was constructed,visually illustrating the spatial distribution of underground geological anomalies.The study outcomes effectively reveal the morphology of fractured and water-rich rock masses beneath the surface,providing valuable references for tunnel construction designs.