Design of Base Isolator for R.C.C. Buildings & Performance Evaluation

Abstract

The main objective of earthquake engineering is to design and build a structure in such a way that damage to the structures and its’ contents during earthquake is minimized. The traditional method’s often results in high floor accelerations for stiff buildings or large inter-storey drifts for flexible buildings. The concept of base isolation is adopted to reduce such kind of inter-storey drifts and high floor accelerations. In addition, isolator does not allow the earthquake energy to enter the building by providing flexibility which decouples it from the earthquake motion. The paper is aiming towards design of different types of base isolators namely, Lead Rubber Bearing (LRB), High Damping Rubber bearing (HDR) and Friction Pendulum System (FPS). A G + 4 symmetric R.C.C. building has been taken for the study. The analysis of the R.C.C. building has been carried out with the commercially available software ETABS 8.11. The design of base isolators has been carried out broadly based on the guidelines of IBC 2000 within the spirit of Indian design standards. In addition to the design of Base isolators, a comparison between Fixed based & Base isolated R.C.C Building has been carried out in the form of Seismic forces, displacements & drifts at various levels of building.