Optimization of Extradosed Bridge and Analysis of Parameters' Sensitiveness as a Case Study on Abay Bridge

The paper describes analytical sensitivity analysis and structural optimization for Abay extradosed cable‐stayed bridge. Identify significant design variables using sensitivity analysis by considering cable stiffness, girder weight and stay cable tension force. The aim of the study is weight minimization of superstructure components of Abay bridges. It has span length (100+180+100) m. For structural optimization, it was carried out by taking total material weight of girders, pylon and stayed‐cable as an objective function and all requirements of strength, stability, serviceability, and fatigue as constraint functions. The formulated optimization problem was coded into Matlab R2019a software and analysis results are retrieved from MIDAS CIVIL 2019 software. The paper gives more reduced weight of bridge from conventional design output by using same material grade. The result shown that optimum stay cable length was reduced from conventional design output by 10% from total values, optimum design of pylon height reduced weight of conventional design by 20.03% and optimum design of box girder reduced girder weight by 19.47%.