隧道超前预报跨水平钻孔地震CT正演技术  

Research on Horizontal Borehole-crossing Seismic CT Forward Modeling Technology for Advance Forecast of Tunnel

作　　者：宋振东 汪文强 张新平 SONG Zhendong;WANG Wenqiang;ZHANG Xinping(No.1 Engineering Testing Institute of Chengdu Engineering Testing Co Ltd,China Railway Eryuan Engineering Group Co Ltd,Chengdu Sichuan 610083,China)

机构地区：[1]中铁二院工程集团有限责任公司检测公司工程检测一所,四川成都610083

出　　处：《中国铁路》2021年第12期115-119,共5页China Railway

摘　　要：随着我国铁路网不断完善,未来铁路建设将重点在铁路交通相对匮乏的西南山区开展。西南山区铁路多以深埋隧道工程为主,岩溶、活动断裂、富水破碎带等不良地质突出,施工风险高,也对超前地质预报的精准度提出了更高要求。目前国内外常用的隧道超前地质预报技术如地震波反射法、地质雷达法、时域瞬变电磁法等均是在已开挖面布置观测系统,其精度会随探测距离的增加而衰减。模拟一种基于射线理论的跨超前水平钻孔地震CT技术,利用透射波进行孔间层析成像,跨超前水平钻孔地震CT技术分辨率高,可实现对隧道开挖掌子面前方地质情况的高精度探测,准确预报异常地质情况,保障隧道施工安全。With the continuous development of railway network in China,the railway construction in the future will focus on the southwest mountainous area in which railway transport is relatively less developed.Railway construction in southwestern mountainous area is mostly deep burying tunnel works,with significant unfavorable geological conditions such as karst,active fault,and water-rich fracture zone,leading to high construction risk.Therefore,greater accuracy of advance geological forecast is required.At present,all the advance geological forecast technologies commonly used at home and abroad in tunnels,such as seismic reflected wave method,geological radar method and time domain transient electromagnetic method,are to provide observation system on the excavated surface,the accuracy of which will attenuate with the increase of detection distance.An advance horizontal borehole-crossing seismic CT technology based on radiographic theory is simulated and transmitted wave is utilized for inter-hole tomography.With high resolution,the advance horizontal borehole-crossing seismic CT technology can realize high-precision detection of the geological conditions in front of the excavated tunnel face,accurately forecast the abnormal geological conditions and guarantee the safety of tunnel construction.

关 键 词：交通隧道 跨孔地震CT 数值模拟 隧道超前预报 射线理论 水平钻孔 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]