Seismic Response Of Simply Supported Deck Bridges With Auxiliary Superelastic Devices

In this paper a multi-performance seismic device based on superelastic SMA wires is proposed for the seismic retrofit of multi-span simply supported and continuous deck bridges. The effectiveness of the proposed device has been assessed through a number of Nonlinear Time History Analyses (NTHA) on two bridge structures representative of existing Italian highway bridges. Results have been compared to the seismic response of the bridges in the as-built configuration. Based on the results of this study, the use of SMA-based restrainers determines a significant reduction (by about 70%) of the deck displacements with an increase (by about 50%) of the maximum force transmitted to the piers. Moreover, the SMA-based restrainers are effective in protecting abutments and bearing devices from damage. The use of SMA-based shock absorbers can give rise to a significant redistribution of the seismic force of the deck between all the piers, thus avoiding the failure of the pier with fixed bearing. (C) 2011 Published by Elsevier Ltd.