Investigating the Impact of Lead Rubber Bearings on Sesmic Behaviour in Elevation for Both Regular and Irregular Frames Using ETABS Software

Abstract

Building structures can be effectively protected from seismic activity with base isolations, as is well known. This paper looks into how real ground motions affect RCC moment-resisting frames nonlinear response when lead rubber bearings (LRB) are used. This is accomplished by evaluating 12-storey regular and irregular RCC structures in elevation that have been upgraded with LRB based on local as well as global deformations. The LRB is characterized by key parameters: storey drift, base shear, storey moment, torsion, time period, and frequency. Two-dimensional models of the base-isolated frames are meticulously developed using ETABS software, and a series of response spectrum analysis are executed using diverse earthquake ground motions. The seismic behaviour of both the base-isolated and fixed-base frames are comprehensively assessed, considering isolator drift ratio, normalized base shear, base moment, time period, and frequency. The study shows the enhanced performance of base-isolated frames compared to fixed-base frames.

The results, obtained through analysis conducted with ETABS software, reveal a significant elongation of the building period and a notable reduction in building storey moment, torsion, storey drift ratio, and shear force for the isolated building in contrast to the fixed-base building.