Rapid evaluation of the high-speed railway bridge vertical deformation threshold and train operation safety performance based on the virtual track inspection method

This study proposes a method for analyzing the impact of bridge deformation on the train-track-bridge coupled dynamics from the perspective of dynamic track geometry. First, with the static mapping geometry and the superposition of random track irregularities are used as excitations, a mapping analytical model between bridge foundation deformation and dynamic track geometry is established by combining the vehicle-track-bridge dynamics model and the virtual track inspection model. Second, after analyzing the effect of bridge foundation deformation on the ratio of dynamic and static extremums of the second derivative, the mapping relationship among the amplitude of the bridge deformation, the second derivative of the dynamic track geometry and the vehicle dynamic response is obtained. Finally, based on the driving safety indicators, a threshold determination method applicable to different bridge deformation patterns is proposed. This method, when combined with modern track detection technology, allows for rapid evaluation and is adaptable to complex bridge deformation scenarios.