摘要
目前利用瞬变电磁法(transient electromagnetic method, TEM)进行隧道超前地质预报时普遍将观测系统置于掌子面上,然而掌子面时有岩体掉落,严重威胁工作人员的安全。针对此情况以及隧道超前探测中瞬变电磁数据解译的问题,本文采用一种基于反函数原理的视电阻率解释方法,同时研究观测系统位于掌子面后方对探测结果的影响。首先计算电偶极子的均匀全空间响应,通过矢量叠加得到回线源中心点处的瞬变电磁场;然后基于反函数原理,选取衰减电压z分量进行全域视电阻率定义,采用三维模型对该方法进行验证,并分析视电阻率随观测系统位置移动的变化特征;最后对实测数据进行处理,并与隧道地震波超前预报(tunnel seismic prediction,TSP)成果互相验证。结果表明:本文视电阻率定义方法可有效表征掌子面前方的含水异常体;将测线后移一定距离,并不影响对掌子面前方含水体位置的大致判断,这为隧道超前探测工作的安全做出了保障。
At present,the observation system is generally placed on the tunnel face when the transient electromagnetic method(TEM)is used for tunnel geological prediction.However,the rock mass sometimes falls down on the tunnel face,which seriously threatens the safety of the workers.To solve this problem and the problem of interpreting transient electromagnetic data in tunnel detection,an inverse function based apparent resistivity interpretation method is adopted in this paper,and the influence of the observation system behind the tunnel face on the detection results is studied.First,the uniform full-space response of the electric dipole is calculated,and the transient electromagnetic field at the center of the loop source is obtained by vector superposition.Then,based on the inverse function principle,the attenuation voltage z component is selected to define the global apparent resistivity,and the layered model and three-dimensional model are used to verify the method,and the change characteristics of the apparent resistivity with the moving of the observing system are analyzed.Finally,the measured data are processed and verified with tunnel seismic prediction(TSP)results and site excavation results.The results indicate that the apparent resistivity definition proposed in this study can effectively characterize water-bearing anomalies ahead of the tunnel face.Moving the measuring line back a certain distance does not affect the rough judgment of the position of water body in front of the tunnel face,which guarantees the safety of tunnel detection.
作者
岳鑫
潘荣国
鲁凯亮
陈兴
武林涛
高扬
樊亚楠
Yue Xin;Pan Rongguo;Lu Kailiang;Chen Xing;Wu Lintao;Gao Yang;Fan Ya nan(Shaanxi Architecture Science Resedrch Institute Co.,Ltd,Xi’an Shaanxi 710082,China;State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,China University of Mining and Technology,Xuzhou Jiangsu 221116,China)
出处
《工程地球物理学报》
2025年第5期499-506,共8页
Chinese Journal of Engineering Geophysics
基金
国家自然科学基金项目(编号:42404154,42504143)
江苏省自然科学基金资助项目(编号:BK20241672)
江苏省卓越博士后计划项目(编号:2023ZB792)。
关键词
瞬变电磁法
隧道超前地质预报
视电阻率定义
transient electromagnetic method
tunnel advanced geology prediction
apparent resistivity definition
