Seismic Responses Of High-Speed Railway Train-Ballastless Track-Bridge System And Train-Running Safety During Earthquake

With the increase of the proportions of high-speed railway bridge which account for the total length of railway line, the probability of earthquakes occurring will be increase when trains are moving over train, the impact of the coupling dynamic interaction of the earthquake action and high-speed train loading on the dynamic response of vehicle-bridge, running safety of the vehicles on bridge will be even more significant, the dynamic behavior of the impact will be more complicated with the increase of the train running speed, it is of great importance for the dynamic response of vehicle-bridge system subjected to earthquake loading and the running safely limit value of the vehicles to study the mechanism of the coupling dynamic interaction. In this paper, based on summing up and absorbing the existing research, the high-speed railkway simply supported girder bridge and CRTS â…¡ slab ballastless track is taken as an example, the dynamic analysis method of the high-speed vehicle-ballastless track-bridge system is established, a computer program is developed, the dynamic design parameters of the high-speed vehicle-ballastless track-bridge system under earthquake action are discussed, the suggested running safely limit values of the high-speed vehicle on bridge under earthquake loading are presented in the paper, which can provide reference for the seismic design of high-speed railway bridge. The following innovative research work is done in this paper.(1)The improved6springs model which can simulate accurately the pile-soil dynamic interaction is presented in this paper by the SHAKE91program and the improved Penzien model, the fine model of high-speed vehicle-ballastless track-box girder-bearing-pier-pile-soil system is built up which can accurately comparatively analyze the influence of the pile-soil dynamic interaction on the seismic response of high-speed railway bridge;(2)The PEER-NGA ground motion waves are introduced into to meet the provision of the Code for Seismic Design of Buildings in which the acceleration time-history curves of the strong motion record and artificial ground motion wave are specified for seismic checking; Based on the ground motion power spectrum model which can satisfy the conditions eliminating the zero frequency content and limiting the energy exchange of the stochastic processes, the calculated program which can produce artificial ground motion wave in different sites is developed, the artificial ground motion waves which can satisfy the computing requirement of the seismic response analysis of the high-speed vehicle-ballastless track-bridge system are presented by comparing with the target response spectrum;(3)Based on the linearized Hertz contact theory and the Kalker creep theory, the rail, ballastless track slabs and base slabs are being brought into the high-speed vehicle-bridge system, the analysis model and method of the high-speed vehicle-ballastless track-bridge coupling vibration to earthquake loading are established, the computer program is developed, the calculating results agree well with the experiment data of dynamic tests at the Beijing-Shanghai High-Speed Railway Sui river super-large bridge, the model can analyze accurately comparatively the dynamic response of the high-speed vehicle-ballastless track-bridge system and running safety index of vehicles, and can anlyze the seismic respose of the vehicle-bridge system;(4)Lots of simulation calculations are carried out to calculate the seismic response of high-speed bridge by the dynamic analysis software of the high-speed railway bridge under earthquake loading, the influence law on the seismic response of high-speed vehicle-ballastless track-bridge system are presented under the different running speed, pier height, site, damping ratio and seismic intensity, the suggested running safely limit values of the high-speed vehicle on bridge during earthquake are presented in the paper under the different running speed, pier height, site, damping ratio and seismic intensity, the influence of the near-field effect and the resonance on the seismic response of the vehicle is analyzed in this paper.