Study On Hydro-geological Characteristics And Water Inflow Prediction Of Tongzi Tunnel In Lanhai Erpressway

During the construction of the tunnel,there may be a series of geological disasters that have a great impact on the construction safety of the tunnel and the operation after the completion.Among them,groundwater has a great impact on the tunnel,and it may cause another geological disasters.Such as sudden water inrush,mud,ground subsidence,collapse,etc.,especially inrush water is the most common and serious.Therefore,in order to reduce the occurrence of these disasters,master the geological structure,the karst development characteristics,the water-rich characteristics of the water-bearing rock group,and the hydrogeological characteristics.Furthermore,analyzed and calculated the amount of water inflow that may occur in the tunnel during excavation.In the way,trying to avoid the safety hazards caused by disasters during construction,and reduce the threat to human property safety caused by sudden geological disasters during operation.This paper takes Chongqing to Zunyi LanHai high speed expansion projects section Tongzi tunnel engineering background.Identify the engineering geological conditions of the tunnel area.Comprehensive analysis of the geological structure of the tunnel site,karst development characteristics,water-rich characteristics of the water-bearing rock group,the characteristics of groundwater recharge and drainage,groundwater dynamics and burial depth,groundwater distribution law and underground river system.The hydrogeological conceptual model and hydrogeological unit division of Tongzi Tunnel are proposed.On this basis,the hydrogeological numerical model of the tunnel study area is established by using FLAC3 D simulation software,and then the water inflow is predicted for each hydrological unit of Tongzi tunnel.At the same time,the atmospheric water infiltration method and groundwater runoff modulus method are used to predict the water inflow of the tunnel.Combined with the actual monitoring data of the excavated section of the tunnel,the comparison with the numerical simulation results is carried out,and the water inflow of the tunnel is comprehensively analyzed.