Seismic vulnerability of masonry arch bridges

Student: Maria Rota
Supervisor: Dr R. Pinho, Prof. A. Pecker

Abstract

Many railway and road bridges in Italy (and, more generally, in Europe) are arch masonry bridges. Recently, new bridges are more often steel or concrete structures, but many masonry bridges are still in use and their seismic performance is a major concern. The potentially high seismic vulnerability of masonry railway bridges has not yet been fully perceived, maybe because there have not been many significant damage evidences after recent earthquakes. While this can be simply due to chance, it is a matter of fact that it is hard to find any specific research study on this subject in the literature. In particular, the problem of the interaction between the infill material and the side walls of the bridges under seismic excitation has not been studied yet, but appears to be a potentially relevant damage mode, in relation with a possible out-of-plane collapse mechanism of the wall. This failure mode is expected to occur at the very beginning of the seismic excitation, before other types of mechanisms may have damaged the structure. Also, it is believed that this kind of out-of-plane collapse may occur even for low levels of acceleration.