Paper Title
A New Hybrid Algorithm for Co2 Emissions Optimization of Retaining Walls

Abstract
This paper presents an effective optimization method for nonlinear constrained optimization of retaining structures. Gravitational search algorithm is one of the latest swarm intelligence based optimization algorithm. A new hybrid optimization algorithm which combines pattern search with gravitational search algorithm (GSA), namely GSAPS, is proposed for optimum design of reinforced concrete retaining walls. There are two alternative phases of the proposed algorithm: the global exploration phase realized by gravitational search algorithm and the exploitation phase completed by pattern search. The numerical experiments demonstrate the efficiency and reliability of the new algorithm. Keywordsó Gravitational Search Algorithm, Pattern Search, Hybrid Algorithm, Retaining Wall, Optimization.