Abstract
In order to reduce the accelerations of top floors for mid-rise base isolations subjected to strong earthquakes, a tuned mass damper (TMD) system is proposed. The performance evaluation results of the existing structures and the previous researches show that large accelerations occur on the roof for the mid-rise base isolations. With a TMD installed on the roof, simulations are carried out for a 10- and 15-story base isolation to investigate the effectiveness of the TMD. The following conclusions are drawn: (1) the TMD is effective in reducing the roof acceleration; (2) optimal parameters exist for the TMD; and (3) a second mode TMD is more effective than a first mode TMD. Finally, a second mode TMD utilizing the top floor is designed, and the practical weight and stiffness of the top floor are discussed followed by the simulation results.
