Stability analysis of elastomeric bearings in bridge structures

Abstract Elastomeric bearings (EB) and lead-rubber bearings (LRB) are used in bridge structures to reduce vehicle vibrations, wind loads, and earthquakes. Therefore, studying their stability is crucial to ensuring the stability of the bridge system itself. Building upon previously proposed linear and partially nonlinear models, two fully nonlinear models suitable for EBs and LRBs are proposed in this paper. The models are developed to adequately account for the interaction between the horizontal and vertical loads and their effect on the bearing’s performance. This study considers that the horizontal and vertical loads do not always act in isolation and that their interaction can significantly affect the bearing’s overall behavior and stability. Comparisons with experiments demonstrated that the models could accurately replicate the behavior of seismic isolators. Additionally, analytical models are developed to predict the horizontal and vertical stiffnesses as a function of the critical buckling load. The two mathematical models can readily be incorporated into open-source structural analysis software, such as OpenSees.