Seismic Performance of Conventional Girder Bridges in Moderate Seismic Regions

Abstract

The majority of continuous girder bridges in regions of moderate seismicity were designed before the introduction of modern seismic codes that prescribe seismic design verification for such structures. The objective of this study is to investigate the seismic performance of typical Hungarian continuous girder bridges through a parametric study. A design space is described by a set of eight parameters. More than 10,000 bridge archetypes are designed without any seismic verification to mimic the design of conventional bridges. The seismic performance of each archetype is then evaluated with modal response spectrum analysis of a detailed finite-element model. The results highlight the vulnerability of piers and bearings and imply that the superstructures are not expected to fail under moderate ground motion intensities. Long bridges with short piers and large spans show the worst performance, especially if the number of fixed bearings in the longitudinal direction is small. This indicates the large influence of the longitudinal ground motion component on the overall response. Based on the fair performance of the investigated structures, detailed inspection and strengthening of similar bridges in moderately seismic areas is recommended.