Optimum seismic design of cable-stayed bridges based on multi-objective particle swarm optimization

To address the challenges of optimizing cable-stayed bridges under seismic loading, a multi-objective particle swarm optimization (PSO) procedure to optimize load-bearing components of cable-stayed bridges is presented. The procedure integrates numerical computing software MATLAB with finite element analysis software ANSYS. The final goal is to identify the optimal cross-sectional dimensions of towers and girders, as well as the optimal cross-sectional areas of cables and their corresponding pre-tension forces. The goal is achieved by coupling the PSO for global searching, time history analysis or spectrum analysis for dynamic evaluation, and the influence matrix method for determining the cable pre-tension forces. The effectiveness of proposed procedure is validated through a two dimensional (2D) and a three dimensional (3D) symmetric layout bridge. Following that, the design procedure is utilized in the preliminary design of a single tower bridge without backstays located in Pescara, Italy. The results demonstrate that the proposed optimization procedure could be an useful tool to optimize cable-stay bridges under seismic loading.