Optimization of Post-Tensioned Concrete Box Girder Double-Track Railway Bridges Using Genetic Algorithm

In the design of bridge superstructure, weight is an important factor especially in long spans; because reducing weight will reduce seismic forces and cost of superstructure and substructure. Among the prestressed concrete bridges, posttensioned concrete box girder is one of the most common and suitable bridges. Different variables are involved in the design of this type of the bridges. This matter leads to a numerous designs for a particular bridge span length and deck width. So, obtaining the optimum solution by conventional methods is a very difficult and time-consuming work. In this study, post-tensioned prestressed concrete box girder double-track railway bridge superstructure is optimized using Genetic Algorithm (GA) by considering several variables including cross sectional geometry, number of tendons, number of strands per tendon and tendons configuration. Explicit and implicit constraints are formulated according to practical and functional requirements based on AASHTO standard specifications. GA is capable to locate the global minimum in a short time. In this way, optimal solution will be achieved by minimum human effort.

کلیدواژه ها:

Optimization ، Prestressed Concrete ، Railway Bridge ، Box Girder ، Genetic Algorithm (GA)