Property Modification Factors for Seismically Isolated Bridges

Abstract

An analytical study investigating how changes in the mechanical properties of individual seismic isolators affect the response of isolated bridge structures subjected to earthquake excitation is summarized. Nonlinear response-history analyses are conducted utilizing bins of recorded earthquake ground motion pairs. Twenty bilinear isolation systems are considered so that the results of this study are broadly applicable to the design of seismic isolation systems in the United States. Variations in the mechanical properties are considered using a property modification factor,