Seismic response analysis of high-speed railway vehicle-slab ballastless track-bridge system under near- fault pulse ground motions

This paper presents a finite element method (FEM) framework for the dynamic analysis of coupled vehicle—bridge systems under nearfield /far-field ground motions. A train car with two bogies is assumed to be represented sufficiently by a discrete, rigid multi-body system with thirty-eight degrees of freedoms (DOFs). The normal Hertzian contact theory and the tangential Kalker linear theory modified by the Shen-Hedrick-Elkins theory is used to establish the dynamic wheel-rail interaction relationship. The triple layered ballastless slab-track is being introduced into the highspeed vehicle-bridge system. Based on the PEER Ground Motion Database, TTBDA, a computer program for the simulation of a high-speed train running on the railway structure under seismic loads, has been developed. The seismic responses of the vehiclebridge system are calculated, and the impact of the near-fault effect on the dynamic responses of the vehicle-bridge system are studied. The case study results demonstrate that near-fault pulse-like ground motions more significantly affect the dynamic responses of the bridge and the running safety of the trains than the nonpulse-like motions of farfield ground motions.