Influence of Longitudinal Connection Mode of Ballastless Slab Track on Vibration Characteristic of Train-Ballastless Slab Track-Subgrade System

A train-ballastless slab track-subgrade vertical vibration mechanical model was put forward based on finite element method. Vibration equations were formulated by using the principle of total potential energy with stationary value in elastic system dynamics and the "set-in-right-position" rule for formulating matrixes. With the vibration mechanical model, influence of longitudinal connection mode of ballastless slab track on vertical vibration responses of train-ballastless slab track-subgrade system under the load case of track random irregularity was studied. The calculated results show that: longitudinal connection mode of ballastless slab track has little effect on vehicle vertical acceleration, rail vertical acceleration, wheel/rail vertical force and fastener vertical pressure force, but has significant influence on vibration characteristic of ballastless slab track structure. Continuous slab and concrete basement can decrease the vibration of ballastless slab track structure significantly.