Modeling and calibration of a High Speed Train Railway Bridge based on in-field vibration data

Today, high-speed trains railway bridges are monitored and analyzed more stringently and detailed to guarantee the reliability and safety of structure. The increase in speed and loads of trains can impose excessive acceleration and displacement or cause resonance in bridge superstructure, which endangers both the integrity of bridge structure and the safety of passengers using the bridge. The thesis presents a calibration procedure for a high-fidelity finite element model of a railway bridge to identify the unknown physical parameters using operational modal data. The detailed 3D modelling can decrease the number of uncertainties in the model. The objective is to modify the influential parameters of the bridge model so that its eigenfrequencies and mode shapes matches, as closely as possible, that of the bridge under analysis. The calibration is realized by parametric analysis and manual tuning the uncertain parameters, such as support condition, to the experimental data achieved through Operational Modal Analysis. Furthermore, the optimized finite element model was utilized in moving load simulations with high-speed train loads according to the passages recorded in order to verify the model and assess the possibility of safely increasing the speed of trains travelling over the bridge. Finally, it is shown that developing a high-fidelity finite element model may help simplifying the model calibration process for a large structure.