水利水电技术2017，Vol.48Issue(10)：18-25,8.DOI:10.13928/j.cnki.wrahe.2017.10.003
大地电磁测深法在深埋隧洞勘察中的应用
Application of magnetotelluric sounding method to exploration of deeply buried tunnel
摘要
Abstract
Aiming at the problems of deeply buried depth,complicated geological and hydrological conditions,complicated and severe land-surface natural conditions,etc.of extra-long deeply buried mountain-crossing tunnel,the magnetotelluric sounding method with stronger topographic adaptability,large exploring depth and certain exploring precision is selected to analyzed the electromagnetic characteristics of various lithologies,fractural structure features,water abundances of rock mass and surrounding rock types in combination with a part of actual cases of the explorations for tunneling project,so as to make the in situ explorations of the engineering geological conditions and the hydrogeological features along tunnel,and then the precisions and reliabilities of the explorations are compared through the methods of construction excavation,drilling,etc.On the basis of this,a judgement criterion is summarized and proposed,meanwhile,the adaptable condition and limitation of the method are analyzed as well.The result shows that the rock mass water abundance of the soft rock with low resistivity is normally stronger and the rock mass resistivity of the hard rock with intense ground water activity is mainly dominated by the property of ground water,for which the effects from the strength and integrality of the rock are weak.Along with the increase of the buried depth,the ground stress is to be gradually increased,while the compaction of rock mass is to cause the gradual increase of the resistivity,thus the water abundance of the deep rock mass is inappropriate to be judged with the shallow-depth resistivity index.The resistivity-based surrounding rock classification standards for the soft rocks of Class Ⅲ,Class Ⅳ,Class Ⅴ are ＞ 200 Ω · m,50 ～ 200 Ω · m and ＜ 50 Ω · m respectively,while the resistivity-based surrounding rock classification standards for the hard rocks those are better than the rocks of Class Ⅱ,Class Ⅲ,Class Ⅳ and Class Ⅴ are ＞5 000 Ω · m,1 000 ～5 000 Ω · m,100 ～ 1 000 Ω · m and ＜ 100 Ω · m respectively.On the whole,the magnetotelluric sounding method is a more effective exploration method for the deeply buried underground project,thus can be taken as a reference for the similar tunneling project.关键词
大地电磁法/深埋隧洞/勘察技术/地层岩性/断裂构造/富水性/围岩类别Key words
magnetotelluric sounding method/deeply-buried tunnel/exploration technology/stratum lithology/fracturing structure/water abundance/surrounding rock classification分类
交通工程引用本文复制引用
贾国臣,刘康和,周明..大地电磁测深法在深埋隧洞勘察中的应用[J].水利水电技术,2017,48(10):18-25,8.基金项目
国家重点研发计划项目(2016YFC0401801) （2016YFC0401801）
