Calculation and Evaluation on Dynamic Characteristics of Bridge-Subgrade Transition Section in Speed-up Railway Line

Combined with the reconstruction of the existing railway line with speed of 200km/h, a calculation model of bridge-subgrade transition section was developed by the theory of vehicle-track-bridge/subgrade coupling dynamics. The simulation program was compiled, which could be used to calculate and evaluate the dynamic characteristics of transition section in speed-up line. The results of field reconnaissance operations and calculations show that the track structure stiffness in transition section is uneven, or even part of the function fails, which can not meet the requirements of speed-raising. Some measures, such as transition section database establishment, class-based management implementation, separate design and separate reinforcement adoption, can be used for the transition sections, which are listed as the objects of emphatic assessment. In addition, the evaluation system will provide theoretical support and references for design and construction in reconstruction project of transition section.