Study On The Influence Of Underground Water Toconstruction Of Mountain Tunnel And Control Measures

With the continuous development of infrastructure construction in China,the advantages of the tunnel as a result of the linear connection between the two places,and not occupying the ground space have been developed rapidly.However,many factors affect the quality of tunnel engineering,the groundwater is one of the most prominent factors,long-standing tunnel problems caused by groundwater,in the tunnel construction project,often water inrush,gushing water and other secondary disasters,once the disaster often cause very serious consequences,if mishandled on groundwater tends to itself and the surrounding nature the construction of the tunnel environment have a profound impact.Therefore,it is necessary to study the relationship between rock and water,and grasp the law of groundwater movement.Based on the tunnel of Yang Jiao Ao,this paper introduces the problems encountered in the construction process and the countermeasures.The main contents of this paper are as follows:(1)The occurrence of water inrush accident is because the newly excavated tunnel changes the way of seepage before groundwater.The new seepage field needs 1-5 years.During the construction of the tunnel,the waterproof layer should be constructed to minimize the influence of tunnel construction on the natural environment.(2)Using BP neural network to predict tunnel water inflow,it is found that tunnel length,permeability coefficient,water column height and radius of influence are important factors affecting tunnel water inflow.In the prediction of water yield in the Yang Jiao Ao tunnel,the BP neural network is used to establish the prediction model of tunnel water inflow.The maximum error percentage is 3.19%,and the numerical value is more accurate,which can be used to guide tunnel construction.(3)Because BP neural network does not need to establish complex finite element models in the process of computation,we can get the prediction results by directly importing geological exploration data.The prediction method is simple and feasible,and can be applied to practical engineering practice.(4)Calculated that when the tunnel excavation by grouting pre reinforcement,rock fracture filling slurry plugging seepage path,the formation of waterproof curtain in the tunnel,which can effectively reduce the tunnel water inflow,but with the further increase of grouting circle thickness,seepage path continues to lengthen,the tunnel water inflow has little influence on the improvement of the tunnel grouting.Water is not obvious,so there is a different grouting effect is more economical and reasonable grouting circle thickness.(5)Through the analysis of the influence of surrounding rock and lining grouting,tunnel excavation of surrounding strata with pre grouting reinforcement of the surrounding rock fracture by grout broken rock together,the mechanical properties of surrounding rock mass has been significantly improved,through calculation and analysis,grouting reinforcement of surrounding rock deformation is obviously reduced,and with the increase of grouting circle thickness the grouting pressure resistance ability to further enhance the load on the lining is obviously reduced,is conducive to the tunnel construction and post operation safety.