Seepage Analysis Of Groundwater And Study On Treatment Measures Of Pouring Water In Wuduxi Highway Tunnel

Water-gushing is one of the most attentive problems in tunnel construction. In recentyears, with the development of tunnel’s design, construction technology and machineryequipments, many design schemes for long distance and deep buried tunnels are constructedin mountainous, underdeveloped western regions with bad transportations. Water-gushingcause great security risk and huge economic losses to the tunnel construction and operationand the problem become more and more prominent and is imminently to be solved.Taking on WuDuxi tunnel for Cheng-Wu highway as the basis, for gushing problemsthis paper combining the methods of theoretical research and analysis, numerical simulation,field monitoring and field test to study. It is proposed that the main factors of gushing arelarge depth for tunnel, spare vegetation covering for mountain, good connectivity of rockfissures, large groundwater storage. The theoretical calculation of WuDuxi tunnelwater-inflow amount is calculated by four kinds of forecasting methods, the results show thatforecasting results of groundwater dynamics method is closest to the actual water inflow.Using GTS numerical simulation to study on tunnel water pressure, water-inflow amount, andchanges in stress, displacement and seepage flow amount after the tunnel excavation and thetunnel grouting. After grouting flow velocity was significantly reduced. Stress field analysisshowed that the stress state of tunnel rock grouting has been a qualitative improvement.Minimum principal stress is minimum during tunnel excavation and is significantly increasedafter grouting and early support. Maximum principal stress is opposite to minimum principalstress. It is because engineering properties of rock had improved significantly after grouting.Improving its ability to resist deformation and keeping the rock stress from releasing. Itevaluates the relationship between the parameters of gushing grouting circle and seepageflow amount and using GTS to calculate seepage flow amount. It indicates that when usinggrouting circle parameters of5m thickness and permeability coefficient of0.00232m/d, notonly can effectively control the seepage flow, but also for grouting materials and constructiontechnology requirements are not so high. The measure is more economical and reasonable.Finally, the tunnel waterproofing and drainage measures is studied and proposed, WuDuxitunnel using a combination of curtain grouting ahead, initial support, radial grouting, partialgrouting, waterproof board, concrete lining, central sewer and drainage facilities and othermeasures to prevent the outflow of gushing water, watering, water leaks and cracks water intunnel. The desired effect was achieved by the method and the entire tunnel achieved the goalof no seepage and no leak. It provides a reference for gushing tunnel of similar geologicalconditions in future.