航空电磁法在川藏铁路隧道勘探中的应用  

Application of Airborne Electromagnetic Method in Tunnel Exploration in Sichuan-Tibet Railway

作　　者：李坚[1] LI Jian(China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道工程学报》2020年第4期1-5,共5页Journal of Railway Engineering Society

摘　　要：研究目的:川藏线雅安至林芝段因地形陡峻和高寒缺氧等问题,人员无法到达隧道上方地面线位采集资料,相当部分地段将会出现勘探资料空白。为此经过研究论证,采用代表国际先进技术水平、由加拿大Geotech公司研发的航空瞬变电磁(VTEM)法和航空天然场电磁(ZTEM)法系统,对隧道进行航空电磁法试验和勘探,以期摆脱相当部分隧道没有勘探资料的困境。研究结论:(1)测线布置原则:沿线路方向并对称于线路中线不等间距布置11条测线,测线线间距由距中线最近的测线线间距最小逐渐变至距中线最远的测线线间距最大;线路两侧最边缘测线间距为隧道勘探深度的2倍;测线长度在应布置长度的基础上两端各延伸3 000 m;(2)并用VETM和ZETM两种方法进行隧道物探,可解决隧道勘探深度变化大的难题;(3)在川藏铁路的初测阶段中,把航空电磁法应用于地形陡峻、高寒缺氧、不能进行地面物探的隧道物探中,取得了较好的效果;(4)本文研究成果主要应用于铁路隧道航空物探领域。Research purposes:Due to problems such as steep terrain and alpine hypoxia,people cannot reach the ground line above the tunnel to collect data,and there will be blank exploration data in a considerable part of the Sichuan-Tibet line from Ya’an to Linzhi.Therefore,through research and demonstration,the airborne transient electromagnetic(VTEM)method and airborne natural field electromagnetic(ZTEM)method developed by Geotech corporation of Canada,which represent the international advanced technology level,were adopted to conduct airborne electromagnetic test and exploration of the tunnel,so as to get out of the predicament that a considerable part of the tunnel has no exploration data.Research conclusions:(1)Layout principle of survey lines:11 survey lines are arranged along the route direction and the middle line of symmetrical lines with unequal spacing,and the survey line spacing gradually changes from the minimum line spacing nearest to the center line to the maximum spacing furthest from the center line;The distance between the most marginal survey lines on both sides of the line is 2 times of the exploration depth of the tunnel.The length of the measuring line shall extend for 3000 m at both ends on the basis of the length to be arranged.(2)Both VETM and ZETM were adopted to conduct tunnel geophysical exploration,which solved the problem of large variation of tunnel exploration depth.(3)In the preliminary survey stage of Sichuan-Tibet railway,the application of airborne electromagnetic method to tunnel geophysical exploration with steep terrain,alpine hypoxia,and no ground geophysical exploration,has achieved good results.(4)The research results are mainly applied in the field of railway tunnel aerogeophysical exploration.

关 键 词：川藏铁路 隧道勘探 航空电磁法 航空瞬变电磁法 航空天然场电磁法 

分 类 号：U212.2[交通运输工程—道路与铁道工程]