Abstract:
The present paper proposes an hybrid base isolation system referred to as BRB+NFVD+BIS, consisting of the buckling restrained braces (BRB), nonlinear fluid viscous dampers (NFVD), and base isolation system (BIS) to study both the damping and isolation effects of the hybrid base isolation system on prefabricated high-rise buildings. Defined are the ratios of both BRB yield strength to base isolation yield strength and the total damping index of NFVD to base isolation yield strength, respectively designate as
BIR and
NIR. Based on the dynamic elastic-plastic seismic response analysis of the corresponding systems, the effects of
BIR,
NIR, and NFVD parameters on the seismic performance of BRB+NFVD+BIS tall buildings have been revealed, and the ranges of
BIR,
NIR, and NFVD parameters are suggested. Results demonstrate that with respect to the non-isolated prefabricated high-rise buildings, the BRB+NFVD+BIS system can significantly enhance the seismic performance of beam-column connections, reduce both the inter-story drift ratios and floor accelerations of the superstructure. Compared with the base-isolated prefabricated high-rise structures, the BRB+NFVD+BIS system substantially reduces base isolation layer displacement while maintaining almost the same seismic performance to each other in terms of the beam-column connections, inter-story drift ratios, and floor accelerations Therefore, the BRB+NFVD+BIS system processes better displacement control ability of isolation layer. Simultaneously, the results show that the BRB+NFVD+BIS system has better robustness of both the seismic mitigation and isolation.