Comparison of different models for high damping rubber bearings in seismically isolated bridges

Research output: Research - peer-reviewArticle

Steel-reinforced high damping natural rubber (HDNR) bearings are widely employed in seismic isolation applications to protect structures from earthquake excitations. In multi-span simply supported bridges, the HDNR bearings are typically placed in two lines of support, eccentric with respect to the pier axis. This configuration induces a coupled horizontal-vertical response of the bearings, mainly due to the rotation of the pier caps. Although simplified and computationally efficient models are available, which neglect the coupling between the horizontal and vertical response, their accuracy has not been investigated to date. In this paper, the dynamic behaviour and seismic response of a benchmark three-span bridge are analysed by using an advanced HDNR bearing model recently developed and capable of accounting for the coupled horizontal and vertical responses, as well as for significant features of the hysteretic shear response of these isolation devices. The results of the analyses shed light on the importance of the bearing vertical stiffness and how it modifies the seismic performance of isolated bridges. Successively, the seismic response estimates obtained by using simplified bearing models, whose use is well established and also suggested by design codes, are compared against the corresponding estimates obtained by using the advanced bearing model, to evaluate their accuracy for the current design practice.

Original languageEnglish
Pages (from-to)329-345
Number of pages17
JournalSoil Dynamics and Earthquake Engineering
Volume104
Early online date11 Nov 2017
DOIs
StatePublished - 31 Jan 2018

    Research areas

  • bridges, high damping natural rubber (HDNR) bearings, multi-span simply-supported (MSSS) deck, seismic isolation, simplified models, vertical behaviour

View graph of relations