Abstract:

Recent earthquakes have enforced the engineering community to design seismically more efficient buildings through the energy dissipation systems. For this purpose, this paper investigates the seismic behavior of a high-rise building with a series of base isolation systems. Firstly, a 20-storey steel frame is selected as a fixed-base building, and then equipped with lead rubber bearings (LRBs). In the modelling of LRB, isolation period is alternatively varied as 4, 4.5, and 5 sec to evaluate the effectiveness of the isolator characteristic on the seismic performance of the high-rise base-isolated buildings. The seismic responses of the fixed-base and base-isolated buildings evaluated through a series of time-history analyses are performed using natural ground motion records. The analysis results are compared using engineering demand parameters such as storey displacement, isolator displacement, relative displacement, roof drift, interstorey drift ratio, absolute acceleration, base shear, base moment, input energy, and hysteretic curve. It is revealed that adjusting the isolation period in the design of LRB improved the seismic performance of the base-isolated high-rise steel buildings.

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