Analysis of the Hydrogeological Conditions of Jungong Super Long Tunnel and Prediction of Its Water Inflow
The survey work for Jungong super long tunnel of the GDSC-2 section of the G227 Guide to Dawu Highway Project was completed in May 2022.The total length of Jungong super long tunnel is 12 km,and most of the area where Jungong super long tunnel is located is in high mountain areas.Island shaped permafrost is widely developed in areas above an altitude of 4,000m.Affected by the high cold and humid climate,evaporation is relatively weak,and atmospheric precipitation(rain)is relatively abundant.A large amount of precipitation directly seeps into the underground along cracks and pores to form frozen layer water,with moderate hydrogeological conditions.In this survey,three engineering geological(and hydrogeological)survey holes were set up for the tunnel body,namely ZK06,ZK07,and ZK08.The hole depths were 338m,211m,and 124m,respectively,with a borehole diameter of 75mm.After the drilling construction reached the design hole depth,bucket pumping tests and aquifer division were carried out in the ZK06,ZK07,and ZK08 boreholes respectively(generally considered as aquifers in areas with broken rock cores and developed joint fractures),calculating the hydrogeological parameters(permeability coefficient K,depth reduction S,water inflow Q,influence radius R,etc.)within the area.Based on the obtained hydrogeological parameters,the groundwater balance method and groundwater dynamics method are used to calculate and predict the tunnel water inflow.The left tunnel water inflow is 13,214.1m3/d,and the right tunnel water inflow is 13,192.5m3/d.
Jungong super long tunnelHydrogeological conditionsHydrogeological parametersTunnel water inflow
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