Effect of Different Scaling Methods on Seismic Isolator Behavior

Abstract

This study investigated the maximum displacement, force, and acceleration values occurring at the isolation level in structures with lead rubber bearings using nonlinear response history analyses. Earthquake records used in the dynamic analysis were scaled with four different methods. In order to perform bi-directional analysis, both horizontal components of the earthquake records were applied to the isolation units simultaneously. In the analysis, the loss of strength (deterioration) due to the heating in the lead core due to the cyclical motion has been considered. In addition, in seismic isolated structures, five periods (Tiso=2.5s, 2.75s, 3.0s, 3.25s, and 3.5s) representing the isolation period, and four characteristic strength ratios (Q/W=0.75, 0.90, 0.105 and 0.120) representing the strength of the isolation unit were taken into account. As a result of the study, 10-13% change was observed in the maximum acceleration and displacement values at the isolation level due to different scaling methods. In addition, there was a 3% change in force results, and no significant difference occurred.