隧道富水断层破碎带突涌预报与工程对策研究

Study on Forecasting and Engineering Countermeasures for Inrush in Tunnel Water-Rich Fault Fracture Zones

为解决高原隧道断层破碎带易发突泥冒顶灾害的问题,采用现场调查、地面物探、洞内地震波反射法、瞬变电磁法、超前钻孔等超前地质预报方法,推广洞内物探三维分析,对富水断层破碎带突泥灾害特征、超前地质预报综合成果和工程应对加固措施进行研究。结果表明:三维物探成果能快速精准查明富水破碎带空间形态,成果直观,有效指导风险判识和工程处置措施;对富水断层带预报应充分结合勘察期成果,宏观初判断层分布特性,洞内采用物钻结合、长短结合的方法;首次提出按照“探明破碎带规模形态,查明破碎带物质组分性状,观测地下水特征变化情况”的思路,研判突泥涌水风险;施工处置应按照“探泄结合,先固后进,回堵再泄”的总体原则有序开展。研究成果和手段可为类似突涌灾害超前地质预报和工程应对措施提供参考。

To address the issue of sudden mud inrush and roof collapse hazards in fault fracture zones of plateau tunnels,various advanced geological prediction methods were employed,including on-site investigations,ground geophysical exploration,in-tunnel seismic wave reflection method,transient electromagnetic method,and advanced drilling.This study employed 3D modeling analysis of in-tunnel geophysical exploration and investigated the characteristics of mud inrush hazards in water-rich fault fracture zones,the comprehensive outcomes of advanced geological prediction,and engineering reinforcement measures.The results show that three-dimensional geophysical exploration can quickly and accurately identify the spatial morphology of water-rich fracture zones,providing intuitive results that effectively guide risk identification and engineering response measures.For predicting water-rich fault fracture zones,it is essential to fully integrate the results from the investigation phase,conduct a macro preliminary assessment of the distribution characteristics of the fault zones,and adopt a combination of in-tunnel geophysical and drilling methods with both long and short-range techniques.For the first time,a strategy was proposed to assess the risk of mud inrush and water gushing by identifying the scale and morphology of the fracture zone,analyzing the material composition of the fracture zone,and observing changes in groundwater characteristics.Construction and mitigation efforts should follow the overall principle of"combining exploration and drainage,stabilizing first and then advancing,and backfilling before draining".The research results and methodologies in this paper can serve as a reference for advanced geological prediction and engineering countermeasures for similar sudden inrush disasters.