Vehicle-Track-Bridge Interaction Effect in the Dynamic Response of Existing Railway Bridges

The work presented herein is devoted to the analysis of the vertical acceleration response of high speed railway bridges composed by multiple simply-supported spans of short to medium length.In this regard, the investigation focuses on the adequacy of using highly detailed three-dimensional finite element models of the bridge for the prediction of the structural dynamic response under operational conditions.A particular bridge configuration is evaluated: pre-stressed concrete simply-supported girder bridges with high levels of obliquity.The presented bridge numerical model include: (i) a detailed discretisation of the track platform; (ii) transverse diaphragms at the span ends; and (iii) successive oblique simply-supported spans weakly coupled through the ballast track layer.To this end, digital twins of two real bridges of 15 and 25 meters span length are implemented and calibrated with experimental measurements.Different approaches for the railway vehicle are assumed to quantify the agreement between experimental and numerical predictions: (i) the simple moving load model; (ii) a multibody three-dimensional vehicle model accounting for the vehicle-bridgeinteraction effect and the track irregularities.Conclusions regarding the dynamic performance and the influence of vehicle-bridge-interaction effect are finally presented.