Influences of seismic excitation and train speed on dynamic performance of train-track-bridge coupled system

With the expansion of China high-speed railways (HSRs), the service performance of CRTS Ⅲ slab track on bridge under earthquake and the operation safety of HSRs are becoming increasingly prominent. To investigate the influences of seismic intensity and train speed on the dynamic performance of train-track-bridge coupled (TTBC) system, the TTBC system model is established and validated based on the finite element (FE) method. This study analyzes the dynamic performance of TTBC system and the running quality of train, under seismic excitation. The lateral and vertical displacement of the slab track increases with seismic intensity. When seismic intensity exceeds 0.05 g, the lateral and vertical accelerations of bridge under four typical types of seismic waves exceed the specified limit. When the seismic intensity of Tianjin-Ninghe waves exceeds 0.3 g, the derailment coefficient, wheel load reduction, and lateral wheel rail force surpass the specified limit. The trends in lateral and vertical displacement of the slab track under different train speeds are consistent. When the train speed exceeds 300 km/h, the derailment coefficient and wheel load reduction exceed the specified limit. The influences of seismic intensity on the dynamic performance of bridge are more significant than that of train speed. The results provide significant reference for ensuring the service performance of TTBC system under seismic excitation.