摘要
我国水资源地理分布的极度不平衡使得修建大型跨流域调水系统成为合理配置水资源的必要举措。在调水工程建设前期,对深埋长大输水隧道的构造勘察是稳定线位、确定投资的重要前提。音频大地电磁法作为一种经济、高效的物探方法,在高原输水构造勘察中亦有多个成功应用的先例。本研究针对西部高原某跨流域调水工程开展基于音频大地电磁法的高原输水隧道构造勘察,通过在数据处理与地质解译中引入基于周边点约束和粒子群算法的伪二维反演、基于电阻率剖面的梯度异常提取和基于岩体完整性系数的隧道围岩等级划分三项关键技术,对电阻率反演结果进行了深入剖析与探讨。针对提出的反演技术,利用数值模型开展了有效性验证,并通过与商业软件反演效果对比验证了反演技术在反演速度和效果方面的优越性。最终,经多技术综合解译,有效圈定了勘察区内断层破碎带的位置展布、土石界线的分布深度以及各区域的围岩等级,为钻探布孔、建设投资以及后期施工风险评估和工艺选择提供了参考。
The severe geographical imbalance in water resource distribution across China has made the construction of large-scale inter-basin water transfer systems an essential strategy for rational water allocation.In the early stages of such projects,structural investigation of deeply-buried,long-distance water conveyance tunnels is a critical prerequisite for route stabilization and investment deter mination.The audio-frequency magnetotelluric(AMT)method,as a cost-effective and efficient geophysical prospecting technique,has been successfully applied in several cases for investigating water conveyance structures in plateau regions.This study focuses on the application of the AMT method for structural investigation in a plateau water conveyance tunnel in an inter-basin water transfer project in western China.Three key techniques were introduced to data processing and geological interpretation:①pseudo-two-dimensional inversion constrained by surrounding point constraints and particle swarm algorithm(PSO);②gradient anomaly extraction from resistivity profiles;③classification of surrounding rock grades based on rock mass integrity coefficients.These techniques enabled a detailed analysis and discussion of the resistivity inversion results.To validate the effectiveness of the proposed inversion technique,numerical modeling was conducted,and its performance was compared with that of commercial software.The results demonstrated the superiority of the proposed technique in terms of both inversion speed and accuracy.Ultimately,through comprehensive multi-technical interpretation,we successfully delineated the spatial distribution of fault fracture zones,the depth of soil-rock interfaces,and the classification of surrounding rock grades within the investigation area.These findings provide valuable insights for drilling hole placement,construction investment,and subsequent risk assessment and methodology selection during construction.
作者
罗议建
Luo Yijian(China Railway Design Corporation,Tianjin 300251,China)
出处
《工程地球物理学报》
2025年第5期351-360,共10页
Chinese Journal of Engineering Geophysics
基金
中国铁路设计集团有限公司课题项目(编号:2024A0226402)。
关键词
音频大地电磁法
输水隧道
综合解译
青藏高原
audio-frequency magnetotelluric
water conveyance tunnel
comprehensive interpretation
Qinghai-Tibet Plateau
