The Estimation Of Track Vertical Irregularity On Long-span Bridge Based On Inertial Reference Method

Track irregularity is the input, as well as the main stimuli, of the train and track system. With more and more high-speed railways are being built throughout the world, the demands for the substructure like tracks, which affect the body of trains, become more strict. It is not only a matter of track material optimization and layout structure, but also higher standards for the quality detection of track irregularity. To adapt to the complicated geographic features along the railways, highway-railway bridges with the distance between two main arches over 1,000 meters have been built in several countries in recent years. To guarantee the design, construction, function safety and good performance of the highway-railway bridges, in the designing stage, accurate evaluation is very necessary concerning the track geometry under external loads. This dissertation contains the following parts:1. Reviewing on the detection technology for track irregularity, the research on the coupling vibration between train and bridge home abroad, and the development of the calculation method and evaluation indexes of track irregularity.2. Introducing the theoretical base and general idea of the calculation method for vertical track irregularity, and bring up the calculation method for vertical track irregularity based on the inertial reference method.3. Modeling for the train-track vertical coupling system by the multi-body dynamics software UM, with the combination of the detection principle of the track inspection car, to imitate the detection for the vertical track irregularity conducted by the track inspection car, in order to calculate with the responding vibration indexes of the train, and exploring the possibility to calculate the track irregularity based on the inertial reference method.4. Introducing the track spectrum of several countries to present the calculation method of the time-domain samples of track irregularity; inputting the calculation result into the system, and then calculating and analyzing the responding vibration of the train in the mentioned train-track vertical coupling model with different operating routes and speeds from two separate perspectives of time and frequency.5. Based on the inertial reference method and the UM train-track coupling model, calculating the vertical track irregularity during the train passing the bridge, and then calculating and comparing different vertical track irregularity situations of the highway-railway bridges under different speeds, superimposed stimuli and bridge structure indexes.