Analysis And Research On The Value Of Water Pressure Outside The Tunnel Project

The value of external water pressure is the focus of hydraulic tunnel calculation in karst area.The selection of design parameters has a great influence on the design and operation safety of the engineering structure.In the process of practical engineering design and application,blind drainage pipe,single drainage hole and multiple drainage holes of the system are often used to treat the water outside the surrounding rock of the mountain.Based on the actual design case,according to the existing hydrological and geological data,and based on the existing drainage system design,the corresponding three-dimensional finite element seepage calculation model of the tunnel is established according to the axisymmetric problem.The seepage characteristics of the tunnel project under the drainage system are revealed,and the action head acting on the lining structure is proposed.Based on the principle of seepage field,the law of groundwater pressure reduction suitable for the actual situation of the project is proposed,and the corresponding drainage pressure reduction measures and external water pressure values are put forward.