Seismic response of base-isolated buildings: exploring isolator properties

This paper examines the impact of LRB and FPS-bearing isolator properties on the seismic behaviour of base-isolated buildings. A systematic analysis of various factors crucial to the performance of these base isolation systems was conducted. The seismic behaviour is critically reviewed, comparing and contrasting the seismic effects of LRBs and FPBs on the general characteristics of structural responses to earthquakes under dynamic loading. The main factors discussed include the coefficient of friction, radius of curvature, diameter of the lead core, and characteristics of the hysteretic behaviour. A comprehensive review of the available literature reveals that distinct groups of elements play vital roles in the seismic response of buildings equipped with lead rubber bearings (LRBs) and friction pendulum systems (FPSs), as discussed for isolated buildings (IBs). For LRB-isolated buildings, the key parameters include efficient damping, lead core diameter, and initial stiffness to post-yield stiffness ratio. Conversely, for FPS-isolated structures, parameters such as the friction coefficient, radius of curvature, and effective damping are closely associated with the seismic response. Based on an extensive literature review, it can be concluded that highly influential factors in determining the overall behaviour and performance of IB structures include the friction coefficient, radius of curvature in the FPS, initial stiffness, and ratio of pre- to post-yield stiffness in the LRB. This paper serves as a key resource for researchers, engineers, and practitioners engaged in seismic design and retrofitting activities, offering insight into the challenges associated with achieving optimal behaviour in base-isolated structures.