EVALUATION OF TOPOLOGICAL FORMS FOR WEIGHTEFFECTIVE OPTIMUM DESIGN OF SINGLE-SPAN STEEL TRUSS BRIDGES

This paper reports a comparative study on design weight efficiency of single span steel trussbridge topologies subjected to gravity loads. The bridges configured according to ninedistinct topological forms (namely, Pratt, Parker, Baltimore, Petit, K-Truss, Warren,Subdivided Warren, Quadrangular Warren and Whipple) are designed for minimum weightunder various span length requirements of single span truss bridges, and the results obtainedwith these topological forms are compared. The optimization process for each bridgetopological form requires achieving optimal sizing of members as well as determiningcoordinates of the top chord nodes such that the least design weight is attained for thebridge. The design constraints and limitations are imposed according to serviceability andstrength provisions of ASD-AISC (Allowable Stress Design Code of American Institute ofSteel Institution) specification. The optimization algorithm employed is based on simulatedannealing method.