综合物探技术在引水隧洞工程超前地质预报中的应用

Application of Comprehensive Geophysical Exploration Technology in Advance Geological Prediction of Diversion Tunnel Project

由于各种超前地质预报方法都存在一定的局限性,选择适宜的超前地质预报方法及地表探测方法相组合,可以提高超前地质预报的精确性与经济性。通过分析常用的超前地质预报方法及地表探测方法的优缺点,判断其适用范围,并在某引水工程实例中,根据其施工特点,洞内采用地震波法和激发极化法,洞外采用大地电磁法的长短结合、内外结合的探测方案,准确预报了掌子面前方80 m内的破碎、含水岩体及80~350 m的含水背斜构造,指导施工,有效避免了相关风险,提高了超前地质预报的精确性与经济性,可为综合探测方案的选择提供参考。

Each forecasting method has its own certain limitations.Selecting a suitable combination of advanced geological forecasting method and surface detection method can improve the accuracy and economy of advanced geological forecasting.This study analyzes the advantages and disadvantages of commonly used advanced geological forecasting methods and surface detection methods and determines their applicable ranges.In the case of a water diversion project,according to its construction characteristics,seismic wave method and induced polarization method are used inside the tunnel,and magneto telluric method is used outside the tunnel.This comprehensive detection scheme accurately forecasts the fractured and water-bearing rock mass within a range of 0 to 80m ahead of the heading face,as well as the water-bearing anticline structures within a range of 80 to 350m,which can guide the construction and effectively avoid related risks.It improves the accuracy and cost-effectiveness of advanced geological forecasting and provides a reference for the selection of comprehensive detection schemes.