High-speed Railway Bridge Longitudinal With Slab Track Structure Parameters Study

The viaduct and large span bridge have been the main feature of the high-speed railway. As a result of the particularity of the structure for ballastless track and bridge, the ballastless track on the large span bridge is restricted. In order to solve the problem, a new type of ballastless track structure—longitudinal connected ballastless track is introduced, the main feature of which is that the slip bedding is installed between base and bridge, which solves the problem that the vertical additional force of the rail in the temperature load influences the bridge. However, the dynamic performance analysis of longitudinal connected ballastless track subjected to vehicle is less. The dynamic response of the new structure subjected to vehicle is studied in the paper. Through the study of parameter, the paper proposes the appropriate value of some main parameters.Referring to the actual structure of longitudinal connected ballastless track, the research is on the basis of the half-width track. The longitudinal connected ballastless track was treated as a model, in which rail is regarded as a long beam supported by discrete viscoelastic supports; slab as a short beam supported by continuously viscoelastic foundation; base as a long beam supported by continuously viscoelastic foundation; bridge as a Euler beam with the Rayleigh damping. The vehicle is simulated as 6-freedom multi-body model, So are more vehicles. Wheel and rail are connected with the osculation theory. The equations describing the vertical vibration of the system are formulated according to the principle of total potential energy with stationary value in elastic system dynamics and the "set in right position" rule formulating matrixes and simulating program is constructed accordingly with MATLAB. With certain sine wave periodical irregularity as vibrating resource, the vehicle-track vertical vibratory responses are analyzed, and some time-history dynamic response curves of the system are calculated.On the basis of the system model, a study of parameter work is processed, which is mainly about the effects of the model of vehicle, speed of vehicle, irregularity, the damping of CA mortar, the mass per unit length, elastic modulus and thickness of the slab, the stiffness and damping of the cushion under rail, the mass per unit length, elastic modulus and thickness of the base, and proposes the appropriate value of some main parameters of the system.Referring to the foregoing study and the damping rail structure at home and abroad, the paper proposes several measures for reducing the vibration of the system. Comparing to the original structure, the paper proposes some parameters of the system for reducing the vibration of the system.