深埋隧洞超前预报及特征数据三维分析的研究应用

Research application of overcasting and three-dimensional analysis of feature data in deeply buried tunnels

摘要

引水隧洞作为引水式电站建设中的关键项目，开展超前地质综合预报对保障隧洞安全开挖、按时间节点顺利贯通显得十分重要。针对川西某深埋引水隧洞开挖过程中部分洞段存在地应力大、断层破碎带发育、地下水丰富等复杂地质条件，结合地质分析法、TRT法、瞬变电磁法及探地雷达，提出了基于超前地质预报三维信息平台的地质综合预报方法。具体实施步骤为：首先，使用三维地震波法确定隧洞前方不良地质体发育的异常物探响应洞段；其次，对异常洞段进行地质信息分析，并使用瞬变电磁对异常洞段开展多角度复测，并三维化地质及物探信息；最后，结合地质雷达精细探测、地质先验资料的补充，开展对掌子面前方不良地质体发育情况的精确预测。将该方法应用于川西某深埋引水隧洞的超前地质预报中，开挖结果揭示：桩号(隧)6+950—(隧)6+867段围岩完整性差，节理裂隙发育，局部发育小断层，岩体较破碎-破碎，地下水发育，整体为Ⅳ类围岩；桩号(隧)6+867—(隧)6+830段岩体完整性较差，节理裂隙较发育，地下水较发育，岩体局部较破碎，整体为Ⅲ₂—Ⅳ类围岩。应用结果表明：三维超前地质综合预报方法实现了地质与物探相结合、物探方法点、线、面的相结合，精确圈定了隧洞掌子面前方断层破碎带、节理裂隙、富水带等不良地质体的发育范围、空间分布等情况，为隧洞安全、顺利开挖提供可靠的技术依据。

Abstract

As a critical component in the construction of diversion-type power stations, water diversion tunnels require comprehensive advanced geological prediction to ensure safe water diversion tunnels require comprehensive advanced geological prediction to ensure safe excavation and timely completion. This study focuses on a deep-buried water diversion tunnel in western Sichuan, where complex geological conditions such as high in-situ stress, fault fracture zones, and abundant groundwater were encountered during excavation. By integrating geological analysis, TRT(Tunnel Reflection Tomography) method, Transient Electromagnetic Method(TEM), and Ground Penetrating Radar(GPR), we propose a three-dimensional geological prediction approach based on an advanced geological forecasting platform. The implementation procedure consists of three phases: First, 3D seismic wave method is employed to identify tunnel sections with anomalous geophysical responses indicating unfavorable geological features. Second, multi-angle TEM verification and three-dimensional integration of geological and geophysical data are conducted for these anomalous sections. Finally, precise prediction of adverse geological conditions ahead of the tunnel face is achieved through GPR detailed detection and supplementation of prior geological data. Application of this method in the western Sichuan tunnel project revealed: In the section Stake(Tunnel) 6+950—6+867, surrounding rocks exhibited poor integrity with developed joint fissures, localized minor faults, moderately fractured to fragmented rock masses, and significant groundwater presence, classified as Class IV surrounding rock. The section Stake(Tunnel) 6+867—6+830 showed relatively poorer rock integrity with moderately developed joints, less groundwater, and localized fracturing, classified as Class III₂—IV surrounding rock. The result demonstrate that this 3D comprehensive geological prediction method effectively combines geological and geophysical approaches, integrating point-line-plane geophysical techniques. It successfully delineates the spatial distribution and development range of unfavorable geological features including fault fracture zones, joint fissures, and water-rich zones ahead of the tunnel face, providing reliable technical guidance for safe and efficient tunnel excavation.

关键词

三维超前地质预报 / 地球物理 / 地质信息化 / 深埋隧洞 / 不良地质体

Key words

3D advanced geological prediction / geophysics / geological informatization / deep-buried tunnel / unfavorable geological features

Author summay

苏 波(1976—), 男, 高级工程师, 国能四川阿水电力开发有限公司党委委员、副总经理, 学士, 主要从事水工施工技术、地质等方面的研究管理工作。E-mail: [e-mail]

基金资助

中国电力建设股份有限公司科技项目“深部地下空间水平地质勘察与超前地质预报技术与装备”(DJ-HXGG-2023-13)