Seismic response analysis of long-span steel arch bridges

Abstract

The non-linear seismic behaviour of tied, half-tied, and deck-type long-span steel arch bridges is investigated using two- and three-dimensional analytical models. A non-linear time-history analysis, which includes all possible sources of geometric non-linearity, was performed on all models studied. The seismic response of the two-dimensional and three-dimensional models of each bridge type was compared, and the effect of the vertical component of ground excitation was evaluated. Furthermore, the response to synchronous and non-synchronous ground excitation was computed and compared for each bridge type. The study emphasises the importance of performing three-dimensional analysis for all arch bridge types in capturing the effect of coupling among vertical, lateral, and torsional motions. It concludes that the vertical component of ground motion has limited effect on the bridge response, especially for the half-tied and deck-type steel arch bridges, and that non-synchronous ground excitation could increase the member forces considerably, except for tied arch bridges.