富水破碎砂岩隧道涌水预测及施工治理措施研究

Study on Prediction and Construction Measures for Water Gushing in Fractured Sandstone Tunnel with Abundant Water

以新建和顺至邢台铁路工程天河山隧道为研究背景,结合研究区水文地质条件,综合分析现有涌水量预测方法,确定采用地下径流深度法计算隧道正洞正常涌水量,采用佐藤邦明理公式预测最大涌水量,并与实测数据进行对比,提出相应的防突水施工治理措施。结果表明:隧道砂岩层间水为多层地下水,蕴含地下水水量较多,为地下水的富集与地下径流提供了有利条件;预测隧道正常水量约35 973.5 m^(3)/d,最大涌水量约71 947 m^(3)/d,强富水段占比76.5%;预测最大涌水量与实际最大涌水量的呈现较为一致的变化规律,剔除离散点后,实测最大涌水量与预测最大涌水量的比值平均值为1.06,表明采用涌水量预测方法的计算精度满足工程施工准确性要求,对富水破碎砂岩地层具有较好的适应性;提出“超前预报+超前预注浆”的施工治理方案,实践表明,该治理方案效果良好,为隧道的掘进施工提供了无水或低水量环境。

Taking the Tianheshan Tunnel of the newly built Heshun⁃Xingtai Railway Project as the research background,this article comprehensively analyzed the existing methods for predicting water gushing in combination with the hydrogeological conditions of the study area.The normal water gushing of the main tunnel was calculated using the groundwater runoff depth method,and the maximum water gushing was predicted using the Sato Bang Akira formula.Compared with the measured data,corresponding measures for preventing water gushing during construction were proposed.The results indicate that the interlayer water in sandstone is multi⁃layered groundwater,containing a large amount of groundwater,providing favorable conditions for the enrichment and runoff of groundwater.The predicted normal water volume of the tunnel is approximately 35973.5 m^(3)/d,the maximum water gushing is about 71947 m^(3)/d,and the strong rich water section accounts for 76.5%.The predicted maximum water gushing and the actual maximum water gushing show a relatively consistent variation pattern.After removing discrete points,the average ratio of the measured maximum water gushing to the predicted maximum water gushing is 1.06.This indicates that the calculation accuracy of using the water gushing prediction method meets the accuracy requirements of engineering construction and has good adaptability to water⁃rich fractured sandstone formations.A construction control plan of“advanced prediction+advanced pre grouting”has been proposed.Practice has shown that this control plan has a good effect and provides a dry or low water environment for tunnel excavation construction.