Analytical Solution for Steady-State Groundwater Inflow into a Circular Tunnel in Anisotropic Soils

An analytical solution for groundwater flow through a circular tunnel in anisotropic soils is derived based on conformal mapping and can be used to calculate the water flow rate into the tunnel and predict the pore water pressure distribution in surrounding soils. If the vertical and horizontal permeabilities are equal, this analytical solution is reduced to the solution for the isotropic flow condition. This proposed analytical solution is verified by numerical simulations. The water flow rate into the tunnel decreases with a decreasing value of soil permeability in the horizontal direction, and the pore water pressure distribution is distorted due to the anisotropy of soil. This proposed analytical solution provides an efficient approach for estimating the groundwater inflow into a circular tunnel accounting for anisotropic soils.