戴云山隧道涌水量的预测和验证分析

Prediction and Verification Analysis of Water Inflow for Daiyunshan Tunnel

研究目的:戴云山隧道是向莆铁路特长高风险隧道之一,正确预测隧道的涌水量对设计和施工至关重要,本文通过隧道施工期间实测涌水量与勘察期间采用多种方法估算的涌水量进行对比、分析,寻找一种以陡倾角构造裂隙水为主的块状硬质岩体长大深埋隧道的涌水量预测方法。研究结论:(1)戴云山隧道采用的地下水动力学法中的陡倾斜含水层潜水非完整井涌水量公式预测的正常涌水量与施工期间的正常涌水量吻合较好,预测精度为98.6%,洞内各出水点的最大涌水量之和与预测的最大涌水量比值为1.61;(2)实测最大涌水量偏大的原因是初期发生最大涌水时的水源主要来自裂隙、孔隙等的静态水;(3)涌水点的实际分布位置与勘察报告的预测差异较大,今后应重视压扭性断裂附近的次级断层、羽状张性裂隙形成的高压裂隙水;(4)本研究成果可供铁路、公路、水电等行业以陡倾角构造裂隙水为主的块状硬质岩体长大深埋隧道工程勘察借鉴或参考。

Research purposes： Daiyunshan tunnel is one of the high risk tunnels on Xiangtang - Putian Railway, and the correct prediction of water inflow is crucial to the tunnel design and construction. A kind of water inflow prediction method, which feathers for searching fissure water from steep dip angle in hard blocky rock tunnel with deep buried, has been developed on detailed comparison between site observed water inflow and the estimation water inflow that calculated by various methods during investigation stage. Research conclusions： （ 1 ） The actual water inflow of Daiyunshan tunnel during construction corresponds with the predicted water inflow, which was obtained by using the water inflow calculation formula for partially penetrated well in steeply dipping phreatie aquifer from groundwater dynamics. This method has a prediction precision of 98.6% , and the ration of the sum of every water exits to the maximum water inflow predicted in the tunnel is 1.61. （2） The reason why the actual observed maximum water inflow exceeds the prediction value is that the most water inflow in initial stage is mainly from cracks, porosity and other static water. （3） The actual distribution of water gushing point has large different from investigation report. Hence, the high pressure fractured water, which stored in the vicinity of the secondary faults, plumose tension fissure around the compressional torsion fracture, should be paid attention to. （4）The research results can provide references for deep buried tunnel engineering investigation projects which feature for steep dip structural fissure water with hard rocky in railway, highway and hydro industries.