Sizing Optimization of Retaining Wall by Firefly Algorithm

Abstract

Retaining wall is used to retain the lateral pressure of soil and surface loading. It has been widely used for application in civil engineering structure such as fill application, roadway cut, etc. This paper considered a firefly algorithm to find out the optimum size and shape of retaining wall with 7m of height and subjected to various loading (5kN/m², 10kN/m², 20kN/m², 40kN/m²). There are four design variables considered for optimization. The objective is to minimize the weight of the retaining wall without violating the requirement of retaining wall. This paper considered stability check of the retaining wall such as overturning stability, sliding stability, and bearing capacity of the soil under the retaining wall. The result shows that the shape of retaining wall with load of 5kN/m² and 10kN/m² were similar, the body of the retaining wall were rectangular while the shape of retaining wall with load of 20kN/m² and 40kN/m² were trapezoidal. Sliding stability became design control for all loading cases compared by other stability problem (overturning and bearing capacity of soil under the retaining wall). Therefore, it can be concluded that firefly algorithm has successfully been applied to optimize the retaining wall.