Performance-based collaborative optimization design for reinforcement concrete bridge

Bi-level optimization strategy collaborative optimization (CO) strategy is used for bridge system performance-based design. Optimization design process is subdivided into two levels: system level and discipline level. For system level, target function is formulated with the total direct construction cost. For discipline level, In terms of load types and structural seismic performance levels, bridge system design process is decomposed into three disciplines: carrying capacity discipline, E1 earthquake discipline and E2 earthquake discipline. Constraints to every discipline are formulated in terms of corresponding codes demands respectively. In order to examine the feasibility and efficiency of CO, both CO and mono-discipline optimization strategy taking Sequential Quadratic Programming as optimizer are applied to an example of a three span simple supported bridge. The results show that CO has high computing efficiency when achieving the same optimization results, especially for design process involving time-consuming disciplinary analysis process.