Abstract: This paper presents an effective optimization method for nonlinear constrained optimization of retaining structures. The proposed algorithm is based on the particle swarm optimization with passive congregation. The optimization procedure controls all geotechnical and structural design constraints while reducing the overall cost of the retaining wall. To applying the constraints, the algorithm employs penalty function method. To verify the efficiency of the proposed method, two design examples of retaining structures are illustrated. Comparison analysis between the results of the presented methodology, standard particle swarm optimization and nonlinear programming optimization method show the ability of the proposed algorithm to find better optimal solutions for retaining wall tasks than the others
