The solution of unconfined seepage problem using Natural Element Method (NEM) coupled with Genetic Algorithm (GA)

Phreatic line detection is a major challenge in seepage problems which should be solved by iterative solving procedures. In conventional methods such as finite element method (FEM), an updating mesh is needed in each iteration where the qualities of the mesh and the nodal connectivity have significant impact on the results. The main aim of this study is to use a method not to be sensitive to mesh generation.In this study, to obtain the optimal phreatic line by the 4th degree polynomial, Natural Element Method (NEM) and Genetic Algorithm (GA) are implemented. Based on the energy principle, an objective function is defined to control the phreatic line position. In the optimization procedure, NEM is utilized to analyze the problem. NEM is a domain type mesh-free method, adapted to geometry of the problem in each iteration. Results display more convergence and flexibility of the present method in comparison with previous studies.