SEISMIC RESILIENCE COMPARISON BETWEEN TALL BUILDING WITH ISOLATED INTER-STOREY MULTI-TOWER BASE AND ONE WITH AN ISOLATED LARGE CHASSIS

The construction of inter-storey isolated buildings on the top of metro depots is an important method to achieve the demand of transit-oriented development of compact city. The seismic resilience improvement of such type of building has become a popular topic due to the demand of construction of resilient city. Critical issues to be investigated are the influence of the large chassis on the seismic responses and seismic resilience of the isolated structure, the difference between the seismic resilience of the tower and the large chassis, and the influence of tower and large chassis on the seismic resilience of the overall building. The influence of yield ratio on the seismic resilience of such type of buildings is needed to be clarified. In this study, inter-storey isolated multi-tower tall buildings with a large chassis and base isolated tall buildings were designed upon five yield ratios, then nonlinear time-history analysis and seismic resilience assessment are carried out. The results indicate that amplification effect on the seismic responses of inter-story isolated building is observed because of the large chassis, leading to the seismic resilience of inter-story isolated buildings lower than that of base isolated buildings. The composition of repair cost and time are different for the tower and large chassis, the repair cost and time of the tower is mainly caused by acceleration-sensitive non-structural components (ASNSCs), while the repair cost and time of the large chassis is mainly caused by the combination of structural components and ASNSCs. The seismic resilience level of inter-storey isolated buildings increases with decreasing yield ratio, but the effect of yield ratio on the seismic resilience of tower and large chassis are different. The repair cost and time of tower gradually decreasing with the decrease of yield ratio, while the repair cost and time of large chassis was not affected by the variation of yield ratio.