瞬变电磁法探测花岗岩蚀变囊状水体应用研究-《高速铁路技术》

文章信息/Info

Title:: Application Research on Detection of Capsule Water Body Causing in Granite Alteration by Transient Electromagnetic Method

Author(s):: WANG Wenqiang; China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China

Keywords:: transient electromagnetic method|granite|alteration|capsule water body|survey line

摘要:: 西南山区铁路隧道花岗岩蚀变现象极为严重，隧道开挖过程中多次遭遇囊状水体涌水。为探明囊状水体分布，降低施工风险，本文采用瞬变电磁法对囊状水体分布进行探测研究，讨论了瞬变电磁法的测线布置及优化、探测剖面角度和钻孔验证情况。研究结果表明，测线优化后不同角度的瞬变电磁法视电阻率剖面呈现多处低阻圈闭异常区，且分布不规律，结果与钻孔验证、后续开挖结果相吻合，准确探明了囊状水体分布，取得了良好效果。瞬变电磁法在花岗岩蚀变囊状水体预报中，具有可行性。

Abstract:: Granite alteration of railway tunnel in southwest mountainous area is extremely serious, and water gushing from capsule water body occurs many times during tunnel excavation. In order to find out the distribution of capsule water bodies and reduce the construction risk, this paper uses transient electromagnetic method to detect the distribution of capsule water bodies, and discusses the layout and optimization of survey lines, the angle of detection profile and the verification of drilling holes. The research results show that, by the transient electromagnetic method, the resistivity profiles from different angles after the optimization of the survey lines show many abnormal low-resistance trap areas with irregular distribution, and the results are consistent with the drilling verification and subsequent excavation results. The distribution of the capsule water bodies is accurately found out and good results are obtained. The transient electromagnetic method is feasible in forecasting capsule water body causing granite alteration.