Numerical modelling of an existing RC bridge including soil-structure interaction: preliminary results

Bridges are critical components of road transportation networks. Many existing reinforced concrete (RC) bridges, constructed during the 20 th century, are now experiencing material degradation (e.g., corrosion, wear of joints and bearings) and therefore require regular inspection and maintenance to ensure their continued functionality. Following the collapse of the Polcevera Bridge in Genoa, Italy, new guidelines were issued and an extensive nationwide inspection campaign was launched to assess the structural safety of the existing bridge stock. In seismic regions, such inspections are particularly important due to the elevated risk of damage from strong ground motions and earthquake-induced effects. In this context, an existing isostatic multi-span reinforced concrete bridge located in a seismic area was chosen as a case study, and two piers were modelled using OpenSees/STKO. Preliminary results from modal analysis with and without the consideration of the Soil-Structure interaction effect are presented. The seismic input is defined in terms of ground motions, using both natural and simulated spectrum-compatible ground motions obtained using an innovative technique based on a genetic algorithm.