ABSTRACT
Bridges are a sensitive part of railway infrastructure and are subject to deterioration of their materials and support conditions during their life cycle. Regular use and the effects of time can affect the behavior of a structure. Therefore, the condition assessment of these assets is one of the most critical issues for infrastructure operators, aiding bridge integrity management. The present paper aims to study the dynamic structural responses and the soil-structure interaction of a reinforced concrete (RC) railway bridge. For this study, a six-span reinforced concrete bridge with 180 meters in total length, built in the 80s and rehabilitated in 2017, was employed as a case study. The bridge superstructure contains longitudinal beams with rectangular cross-sections, transverse beams, and a concrete deck with variable cross-sections. The infrastructure is composed of caissons supported by a rock layer. A numerical model was developed using the finite element method considering the soil-structure interaction process from Winkler springs calibrated adequately according to soil characteristics and foundation type. The springs, applied on the foundations and bearing devices, were positioned according to design and construction information, which provided physical and mechanical characteristics necessary to develop the computational modeling. Results regarding natural frequencies of vibration, deformations, displacements, accelerations, and velocities in the deck, beams, and pile caps of the railway bridge were analyzed and compared with monitoring results, assessing the bridge’s structural response when subjected to dynamic loads. The numerical results adhered to those found in the monitoring campaign, thus validating the modeling methodology strategy employed in the bridge study. The results can be used to evaluate the structural condition and asses the bridge’s behavior during its life cycle. Therefore, it can support the development of models to predict failures and even be incorporated into a digital twin that can be employed for bridge integrity management.
