Dynamic Characteristics of Coupled Vehicle–Track–Tunnel Interaction System

Abstract

Traditional studies simplify vehicle-track-tunnel system into vehicle-track or vehicle-tunnel models and neglect dynamics influences of vehicle on tunnel through track or track-tunnel on vehicle. This study established the mathematical model of vehicle and finite element model of track-tunnel to disclose vibration characteristics of vehicle-track-tunnel coupled dynamic system. Next, a vehicletrack-tunnel dynamic coupled model was established based on the wheel-rail displacement coordinated relation. Finally, variation laws of vehicle and stress and displacement fields of tunnel surrounding rock when the train travelled at speed of 200 km/h were studied under different track slab stiffness and track structures. Numerical simulation results demonstrate that vehicle vibration indexes change in the linear law with the increase in track slab stiffness. Sleeper embedded ballastless slab track has better damping reduction performance than sleeper buried ballastless slab track. The best damping reduction performance is achieved when the track slab stiffness is 3.5 kPa. The maximum vertical displacement and stress of the tunnel surrounding rock due to vibration at low levels and the tunnel surrounding rock slightly influence vibration indexes of vehicles.