Inspection and Structural Rehabilitation of an Existing Masonry Arch Railway Bridge

Masonry arch bridges are important structures of road and rail networks around the world. Over several decades of service life, they suffer deterioration and damage. In order to preserve their functioning, it is necessary to carry out a seismic vulnerability analysis to verify the current level of safety and, if necessary, take action to reach the standard required by current codes. For these reasons, a structural analysis of the existing railway bridge built with masonry arches, located on the San Nicola-Avigliano Lucania line in Potenza, Italy, was carried out. The seismic vulnerability of the bridge was assessed using the Finite Element Analysis (FEA) method by subjecting a properly discretized three-dimensional model of the entire structure to a non-adaptive nonlinear static analysis (pushover). The obtained results do not meet the minimums suggested by current European Standards. Therefore, a traditional structural rehabilitation intervention was designed and modeled. The intrados of the arches and the bridge piers were reinforced with a thin reinforced concrete slab and reinforced concrete jackets, respectively, all connected to the existing structure by steel bar connectors. By re-performing the pushover analysis of the reinforced structure using FEA software, it was observed that the new risk indexes satisfy the seismic vulnerability verification. Thus, the proposed structural rehabilitation is a valid, but not unique, solution to the problem affecting the existing masonry arch bridge analyzed in this study.