Analytical solution for steady seepage around circular cofferdam in soil layer with anisotropic permeability

The seepage field of circular cofferdam in permeable anisotropic soil layer is analyzed in present study. First, the seepage region around circular cofferdam is divided into three regular parts. The series solutions of water head distribution in three regions in cylindrical coordinate system are obtained by using method of separation of variables after coordinate transformation and homogenization of boundary conditions. And then an analytical solution of steady seepage field of circular cofferdam in permeable anisotropic soil is obtained by utilizing the orthogonality of Bessel function. The solution is verified through the comparison with the results obtained from the finite element software Plaxis2D. Based on the analytical solution, the expressions for seepage quantity and exit gradient are deduced and compared with the results obtained by different methods. Finally, the water pressure under steady seepage is calculated and analyzed. The results show that the seepage quantity, exit gradient and the water pressure obtained by analytical solution are in good agreement with numerical results as compared with results obtained by other methods; the seepage water pressure decreases with the increase of the ratio of cofferdam radius and vertical and horizontal permeability coefficients, and then gradually approaches a stable value.