Numerical Analysis of Free Surface Seepage Problems

The finite element numerical technique is used to effect a solution to linear seepage problems. Particular reference is made to the time dependent movement of a phreatic surface. The flow domain is represented by subdomains composed of isoparametric elements, which permit a close approximation to curved boundaries. The ease of application to seepage through inhomogeneous media is demonstrated during the development of the finite element discretization technique. It is shown that relatively few of the sophisticated isoparametric elements yield solutions to particular flow situations which compare favorably with other numerical and experimental methods for both steady state and time dependent problems. Then generality of approach is shown by particular examples, such as flow towards wells and through an earth dam which amplify the versatility of the particular numerical technique used.