THE EFFECT OF TUNED-MASS DAMPERS ON THE SEISMIC RESPONSE OF BASE-ISOLATED STRUCTURES

The low stiffness of laminated rubber bearings utilized in base isolation could potentially cause large lateral displacements which must be reduced by some energy-dissipation mechanism. The effect of applying tuned-mass dampers towards reducing the lateral deformation of the isolators was studied in this paper. The choice of the proper parameters of the tuned-mass damper and the influence of excitation frequency on the response were investigated. Through the numerical simulation of a five-storey base-isolated building subjected to different earthquake records, it was found that although the tuned-mass damper had little effect on structural response during the first few seconds of earthquake excitation, the damper may add damping to the structure to reduce the subsequent response. The idea of the accelerated tuned-mass damper was proposed and demonstrated the capability of decreasing the maximum deformation of the isolators which occurred at the beginning of earthquake excitation.