3D Numerical Modeling of Subsurface Flow through Rock Drains and Evaluation of Analytical Solutions

In this paper, subsurface flow profiles through coarse porous media have been simulated using a 3-D numerical model with and without surface discharge and their results have been compared with experimental data as well as with analytical solutions. SEEP/3D model, which is based on the finite element method, was used to simulate subsurface flow. The experimental model was consisted of coarse porous media with 6.4 m in length, 0.8 m in width and 1 m in height. The experiments were performed for different boundary conditions with two bed slopes of 4 and 20.3 %. The simulated data of watertableprofiles and seepage discharges were compared with those corresponding experimental data. In no recharge conditions with 4% slope, the numerical data were compared with both experimental and analytical dataindicating that the numerical results underestimated the watertable profilesas compared to the experimental ones. The results was better for the 20.3%-slope. In surface recharge condition, the numerical results only compared with analytical solution of Bear (1972), and the results indicated underestimation as compared to the experimental data.