The Prediction Of Water Gushing And Water Inrush In Complex Karst Tunnel Of Niulan Moutain

There is a complex mechanism and prediction of water inflow with Karst tunnel gushing water,prediction of water inflow and water inrush is one of the difficult problems in the field of hydrogeology for a long time.The underground mine,tunnel and hydroelectric engineering construction in the karst area,often encounter water inrush,and other geological disasters,seriously affect the construction safety and the safe operation of the facilities built,underground facilities of water inflow and water inrush disaster become bottleneck in the karst area underground space construction and development.In this paper,Niulanshan water diversion tunnel as the research object,by comprehensive application of water balance method,groundwater dynamics method and consider a Coupled Seepage Damage of the fluid solid coupling finite element method,the Kraal mountain tunnel water inflow and water inrush are forecasted,the evolution process and mechanism of karst water inrush disaster are discussed.The main work of this paper is as follows:(1)First,a comprehensive analysis of the hydrological geological condition of the tunnel in karst area,according to the karst water,surface and subsurface runoff recharge,the whole cavity section is divided into 18 typical hydrogeological units.From the point of view of hydrogeology of the hydrological geological unit of gushing water and water inrush cases were preliminary judgment.(2)For the typical hydrogeologic unit,the selection of the 23 hole section,first of all,get hole section in the area where the digital elevation model(DEM)from the geographical space cloud,based on the DEM data,reconstruction of the hole section of the area where the 3D surface,then calculate the catchment area of the tunnel section in the region.Finally,the water balance method to predict the hole section of the average inflow and monitoring data were compared.(3)According to the limitation of water balance method in the prediction of water inrush,considering the tunnel excavation near the surface of water gushing to water inrush process flow in the process of excavation by seepage stability to the fast flow to free flow of dynamic process,respectively using equation of Dacry and the Brinkman equation and Navier Stokes equations describe three kinds of flow state,using hydrodynamic methods of underground rivers and caves and karst fracture zone and so on three kinds of typical process water geological unit in the tunnel excavation process of water inrush forecast.(4)Based on tunnel excavation process of seepage damage coupling principle,using flow solid coupling finite element method,the excavation of tunnel surrounding rock in the process of the progressive damage,and based on the method of induce the dynamic process of water inrush,the water inrush of typical tunnel section was predicted.