Dynamic Analysis of Elevated Station Considering Vehicle Longitudinal Effects
|School||Beijing Jiaotong University|
|Course||Bridge and Tunnel Engineering|
|Keywords||Vehicle-bridge interaction Elevated station Dynamic analysis Brakingsystem Braking force Dynamic test Numerical calculation Girder-rail interaction Vehicle-rail-bridge system|
ABSTRACT:With the increasing demand of national economy, the railway construction has developed a lot. The construction scale of railway station is becoming larger and larger, and the elevated railway station, which is a kind of three-dimensional structure, is more widely adopted, thus playing a significant role in the efficient organization of transport and urban construction. On the other hand, this new kind of station structure will bring some new problems. The train passing through the elevated railway station and its frequent braking and starting will lead to the dynamic interaction between the train and the station structure, which will influence the safety of structure and comfort of passengers and staff in the station.Based on the vehicle-bridge vibration theory, the frontier subject in the vibration-engineering field of the vibration responses of elevated high-speed railway station under vehicle load is studied in this dissertation. By establishing a three-dimensional dynamic analytical model of the coupling train-elevated railway station system, the whole process dynamic emulation analysis of a train passing through the station at a high speed as well as its braking and starting is performed.In this dissertation, the transfer mechanism of vehicle load in the elevated railway station is studied and the safety and comfort of the station structure under vehicle load as well as the safety and stability of the train passing through the station at a high speed are evaluated. The main research contents and innovation points are as follows:(1) The developments of the high-speed railway and the elevated railway station are summarized as well as the structures, the characters, the vibration problems and research contents of the elevated railway station. The vehicle-bridge coupling vibration, the dynamic analysis of elevated railway station and the longitudinal dynamic interaction of the train are especially summarized. Some weak points in the research of the vibration of elevated railway station and the longitudinal interaction of train are also proposed.(2) Based on the traditional single-particle analytical model and longitudinal multi-particle model on the longitudinal analysis of train, the longitudinal dynamic analytical model of high-speed EMU is established. Based on this longitudinal analytical model, through the study case of CRH2EMU with the speed of200km/h braking at a7-level service braking, the time-history of braking force acting on the rail surface can be obtained. Meanwhile, the longitudinal dynamic effect on bridge under the train braking is studied. Taking the longitudinal interaction between the bridge and rail into consideration, a longitudinal dynamic analytical model of train-rail-bridge system is established. Taking the typical domestic high-speed train passing through a10-span simply supported bridge paved with gapless rail as a study case, the dynamic responses of the train-rail-bridge system when a high-speed train is braking are obtained.(3) A dynamic analytical model of high-speed train-elevated railway station system considering the longitudinal interaction of train is established. In this model, the train subsystem is modeled as a three-dimensional analytical model on the basis of multi-body dynamics and the motion equation of train considering longitudinal degrees of freedom can be derived. The station structure subsystem is modeled through finite element modeling. The two subsystems are connected through the assumptions of longitudinal, vertical and transverse wheel-rail relations. The resulting system equations can be solved by the whole process iterative method. The train-structure coupling relation is the key to the dynamic analysis of the above system, in which the wheel and the rail are assumed to be closely contacted in the vertical and longitudinal directions and in the transverse direction, the wheel-rail relation is assumed through the simplified Kaller linear creep theory or the wheel-set hunting assumption. The Numerical method is a research difficulty and in this dissertation, the calculation procedure of the whole process iterative method is introduced as well as its differences from and advantages over other methods.(4) A dynamic test on the key parts of the station structure when the train is braking to stop in the station and starting to leave is performed. During the test, the vibration influence due to braking and starting of train on the station structure is analyzed and the test also provides experiment verification for the dynamic emulation analysis of the elevated railway station. The comfort of the station is also evaluated and the preliminary standard of station comfort is studied.(5) Based on the basic dynamic analysis theories of high-speed train-elevated railway station system introduced in Chapter3, with the Nanjing South Railway Station used as a study case, the dynamic response characteristics of the station under different train running status is calculated and analyzed. Combined with the dynamic tests introduced in Chapter4, the calculation results and the measured results under the same braking conditions are compared. Eventually, the vibration comfort of the train and the elevated railway station is evaluated.