Abstract: To study the characteristics of vertical vibration of vehicles-long-span continuous rigid frame bridge，the solution of wheel-track force was automatically figured out based on creep theory in combination with Matlab program.The simulative wheel rail force was then input into the finite element analysis model of bridge to get the vertical vibration of the bridge.The simulation results show that the Mablab-Midas model solution of vertical vibration response of bridge is highly feasible and convenient.Taking a certain large continuous rigid frame bridge as an example,the vertical dynamic responses from the electric motor trains of CRH1,CRH2,CRH3,CH4 are analyzed respectively.Results show that the type CRH4 vertical displacement of the dynamic response is greater than the other three types, but general trend of change on four kinds of models is consistent.

Key words: vehicle-bridge coupled vibration, wheel-track force, vertical vibration, vertical immunity, dynamic response