Design Optimization Of Reinforced Concrete Deck-Girder Highway Bridge

The design of reinforced concrete structures requires the assumption of members dimensions, followed by analysis of the whole structure, then followed by the design of the members. Near optimal structural design has been achieved by trial and error based on experience with structure of similar purpose. Such design solution can be technically fit to perform the purpose what it is designed for, but the solution may not be the optimal solution. A practical optimization approach to the design of reinforced concrete Deck-Girder Highway Bridge is presented in this paper.The approach is entirely based on the American Association of State Highway and Transportation Officials (AASHTO) standard specifications for highway bridges. All behavior and side constraints specified in the AASHTO bridge code are considered in the optimum design process.An optimization formulation using load and resistance design factors is presented. In this formulation, the independent and dependent design variables are identified, and constraints are formulated according to AASHTO standard specifications.The solution for the formulation is obtained by using a nonlinear constrained optimization software.Finally, numerical examples illustrate the application of the proposed approach to the design of reinforced concrete deck-girder, and the results showed that the model and method are reasonable and practical.