Distribution law of seepage field in deep-buried high water pressure class Ⅳ surrounding rock tunnel construction

With the increase of transportation capacity, the construction scale of deep buried tunnel and the depth of buried tunnel are increasing. By selecting four burial depths of 100m, 200m, 500m and 1000m, and taking the seepage field of the deep-buried tunnel under the Ⅳ level surrounding rock as the research object, and using the finite difference software Flac3D for modeling and calculation, the seepage field distribution law of the tunnel under different depths and high water pressure was discussed. It finds that: 1) Under the same topographic and geological conditions, the surface settlement and tunnel depth decrease first and then increase; 2) With the increase of burial depth, the initial support water pressure increases gradually from the arch top along the arch foot, and the main effect of groundwater on the initial support changes from compression to tension. 3) The maximum water pressure of lining is located near the arch foot, and the arch foot water pressure value does not increase linearly with the increase of head height. The research results can serve as reference for doing the drainage and preventive measures in the construction process of the same type of deep buried tunnel.