PERFORMANCE EVALUATION OF LEAD RUBBER ISOLATORS UNDER SEISMIC LOADS

Shankarling S Mandewali, H.Narendra

Abstract: Earthquake is the natural phenomenon that occurs due to sudden movement of the earth surface, releasing tremendous amount of energy which proves to be a curse to the structural integrity and hence to the mankind. In order to safeguard the structural integrity, from the past few decades’ ductility method has been adopted. Ductility method ensures the life safety but structural integrity is not ensured. Hence in order to enhance the structural safety, many structural control concepts have been developed in recent times. Base isolation, Seismic damper etc are some of the structural control concepts which are being used widely nowadays. Base isolation is a passive type of energy dissipation system in which the superstructure and substructure are decoupled by a rubber media known as isolators. The basic principle behind the base isolation system is to elongate the fundamental period of the structure; thereafter the seismic energy transmitted to the structure will be significantly reduced. Thus the superstructure acts as a rigid body and damages to the non-structural elements are also reduced. In the present study, a G+10 reinforced concrete structure is considered, 4 x 4 bays, 5 m in both directions. Non-linear time history analysis of the building is carried out by using SAP2000 computer package. Analysis is carried out for time history records of zone V (confirming to BIS) and El-Centro (N-S component).

Keywords: Base isolation, Lead rubber bearing (LRB), Responses, Non-Linear time history, Fundamental period

DOI: https://doi.org/10.15623/ijret.2016.0526005