Comparison of seismic assessment procedures for masonry arch bridges

The paper delves into the seismic safety assessment of masonry bridges through a detailed analysis of an existing triple-arched bridge. Firstly, the effectiveness of the nonlinear static analysis is evaluated by means of a comparison with a comprehensive set of twenty-eight nonlinear dynamic analyses. Secondly, the choice of the control node on the finite element structural model is investigated, in order to understand its influence on the seismic capacity prediction. Although the node located at the top level is usually considered as the most significant point for the force-drift characterization of common structures, such a choice is not suitable for the considered case-study. The node located on the bridge centre of mass proves to be a better choice since it ensures a more reliable estimation of the seismic capacity. The critical discussion of the numerical analyses results gives a sharp indication toward the establishment of a standard for the seismic assessment of the considered structural typology.