Performance-Based Multiobjective Optimal Seismic Retrofit Method for a Steel Moment-Resisting Frame Considering the Life-Cycle Cost

摘要: This study proposes a performance-based multiobjective optimization seismic retrofit method for steel moment-resisting frames. The brittle joints of pre-Northridge frames are retrofitted to achieve ductility; the involves determining position and number connections be retrofitted. optimal solution is determined by applying nondominated sorting genetic algorithm-II (NSGA-II), which acts as technique. As objective functions, initial cost connection lifetime damage were selected, performance level below 5% interstory drift ratio was employed constraint condition. proposed applied SAC benchmark three- nine-story buildings, several Pareto solutions obtained. optimized indicated that decreased increased. Although every existed within boundary set function, tended increase with cost. Analysis economic assessment relations among cost, total derived allow building owners make decisions more rationally.