Performance of Seismic Base-Isolated Building for Secondary System Protection Under Real Earthquakes

Abstract

Damages due to earthquake can be reduced by controlling the seismic response of structure. For the structures containing expensive equipments such as nuclear power plants, computer centers and hospitals reduction of seismic response of secondary system (SS) is as important as reduction in seismic response of primary structures (PS) since damage to secondary system (SS) leads to significant social chaos. This paper provides the investigation of effectiveness of base isolation technology for secondary system. A three storied reinforced cement concrete (RCC) building is modeled as a PS in this study. Laminated plug bearing is adopted for base isolation of PS. Secondary system is housed at first floor level of the PS. SS is isolated with elastomeric bearing from the supporting PS floor. The earthquake ground motions recorded at Myanmmar border region recording station location 25^°N 95^°E having PGA 0.003 and 0.0021 g are used as input ground accelerations. Seismic responses of SS with and without isolation are evaluated and the effect of interaction between PS and SS is also studied. A remarkable reduction in seismic response of SS is observed when it is isolated.