Earthquake analysis of lead core rubber bearing isolated steel buildings

The safety and damage control are the key parameters in the philosophy of earthquake resistant design. To protect the structures, the utilization of base isolation is one of the economical and practical solutions and it mitigates the seismic load by providing both lateral flexibility and energy dissipation. In this study, the effect of using lead core rubber bearing isolator on the seismic performance of the mid and high rise buildings were investigated. For this, 5, 10, and 15 story steel frame buildings were used as the case study. These buildings had the same plan with 6 bays of 6 m span in x-direction and 3 bays of 6 m, 4 m and 6 m spans in y-direction. These spans of the buildings were selected to indicate the typical residential building spans. Modeling and time history analysis of the base isolated and fixed based cases were performed by means of a finite element program. Three earthquake ground motion records were used in the earthquake analysis. The characteristics in terms of relative displacement, drift ratio and time history variation of some response parameters were studied. From analytical results, it was observed a significant reduction in the seismic response of the isolated buildings as compared to the fixed base cases