Limit analysis of transverse seismic capacity of multi-span masonry arch bridges

摘要

Thousands of road and railway masonry arch bridges are still in service in the Italian and European transportation network, and many of them are located in highly seismic areas. In this work, a kinematic analysis procedure is developed to assess the transverse seismic capacity of multi-span masonry bridges with slender piers, as they may be vulnerable to transverse seismic action. The procedure can calculate the limit horizontal load multiplier of overall collapse mechanisms involving transverse deformation of deck and piers. The procedure is then adopted in a parametric study describing the typical ranges of the main parameters influencing bridge transverse capacity. Parametric analysis yielded a set of iso-acceleration envelope curves which supply the resistant seismic acceleration of a bridge as a function of simple geometric parameters. The resulting graphs can thus be used for preliminary seismic assessments.