Computer-support tool to optimize bridges automatically

Abstract

[EN] In bridge design, many variables like material grades, cross-sectional dimensions, passive and prestressing steel need to be modeled to evaluate structural performance. Efficiency gains are intended while satisfying the serviceability and ultimate limit states imposed by the structural code. In this paper, a computer-support tool is presented to analyze continuous post-tensioned concrete (PSC) box-girder road bridges, to minimize the cost as well as to provide optimum design variables. The program encompasses six modules to perform the optimization process, the finite-element analysis, and the limit states verification. The methodology is defined and applied to a case study. A harmony search (HS) algorithm optimizes 33 variables that define a three-span PSC box-girder bridge located in a coastal region. However, the same procedure could be implemented to optimize any structure. This tool enables one to define the fixed parameters and the variables that are optimized by the heuristic algorithm. Moreover, the output provides useful rules to guide engineers in designing PSC box-girder road bridges.