DEFORMATION COMPATIBILITY RELATIONSHIP OF TRACK INTERLAYER WITH UNEVEN SETTLEMENT OF SIDE PIER OF CONTINUOUS GIRDER BRIDGE AND ITS DYNAMIC APPLICATION

The settlement of the side piers of high-speed railway continuous girder bridges will cause the compatible deformation of the upper simply supported and continuous girder bridges. The change of the track geometry caused by the uneven settlement of the side piers directly affects the running stability and safety of the train. Based on APDL, this paper establishes a refined simulation model of CRTS II type ballastless track continuous girder bridge system with variable cross-section considering the influence of the approach bridge and subgrade and the upper track structure. Through a large number of simulation calculations, the compatibility mechanism of track layer deformation between the uneven settlement difference of the side piers and the change of track geometry is explored. Based on the linear regression method, the quantitative function expression of the interlayer deformation compatibility relationship between the uneven settlement difference of the side pier and the change of the track geometry under different continuous girder bridge spans is obtained. Furthermore, the simulation model, literature model and the train-track-bridge coupling dynamics theory are used to verify its fitting accuracy and correctness. Finally, the influence of uneven settlement of side piers on the running stability and safety of the train is studied based on quantitative function expression. The research results show that the calculation results of the three models are in good agreement, which indicates that the quantitative function expression in this paper has a high accuracy. Under the condition of uneven settlement of side piers, there exists a critical span where the excitation frequency is close to the natural frequency of the vehicle body. When resonance occurs, the train running stability will be significantly affected. Adopting the long-span continuous girder bridge can effectively reduce the uneven settlement difference of side piers, improve riding comfort, reduce wheel-rail force and alleviate the dynamic effect of train and track. When the settlement difference is less than 25 mm, the weight loss rate of the wheel decreases significantly with the increase of the span.