Probabilistic seismic loss analysis for the design of steel structures: Optimizing for multiple-objective functions


An optimized seismic performance-based design (PBD) methodology considering structural and nonstructural system performance and seismic losses is considered to optimize the design of a steel structure. Optimization objectives are to minimize the initial construction cost associated with the weight of the structural system and the expected annual loss (EAL), considering direct economic losses. A non-dominated sorting genetic algorithm method is implemented for the multiobjective optimization. Achieving the desired confidence levels in meeting performance objectives of interest are set as constraints of the optimization problem. Inelastic time history analysis is used to evaluate structural response under different levels of earthquake hazard to obtain engineering demand parameters. Hazus fragility functions are employed for obtaining the damage probabilities for the structural system and nonstructural components. The optimized designs and losses are compared for the structure located in two geographic locations: one in the central United States and another in the western United States.

Publication Title

Earthquake Spectra