Study On The Seismic Calculation Model And Seismic Response Of The Bridge With The Slab Ballastless Track

In recent years, the ballastless track has been widely used in the high-speed railway of our country, especially in slab ballastless track. However, the content of the ballastless track have not been included in the existing railway seismic codes, the seismic design often neglects the effects of the ballastless track. According to the structural features of “Longitudinal plate” on the CRTSⅡ slab ballastless track, “Unit plate” on the CRTSⅠ、Ⅲ slab ballastless track, respectively proposing the simplified model of the three kinds of slab ballastless track to make the analysis of the bridge seismic response, comparing with the traditional calculation model. Based on the above, discussing the effect of the earthquake response of high speed railway bridges under the tack constraints under the multi earthquake and rare earthquake. The main contents are as follows:(1) Through reading a large number of references of the internal and external, introducing the development history, structural characteristics, current research status and the existing problems of the high-speed railway slab ballastless track detailly.(2) Improving the calculation model of the CRTSⅠ、Ⅱ、Ⅲ slab ballastless track on the basic of which proposed in the relevant regulations and documents. Proposing the fine seismic calculation model of rail-bridge, the simplified seismic calculation model of rail-bridge of the slab ballastless track according to the structural features of them. Proposing the equivalent stiffness calculation formula of the subsequent roadbed segment(the friction plate and end-spine) of the CRTSⅡ slab ballastless track and make the detailed description of the layout mode、the value of the calculation parameter and the method used in the modeling process of the three kinds of the slab ballastless track.(3) Taking the double track simply supported box girder-bridge of a certain high-speed railway as the research subjects. Using the response spectrum analysis method, make a comparative analysis of the results of the calculation model and the traditional calculation model which doesn’t consider the tack constraints of the CRTSⅡ slab ballastless track. Based on the above,proposing the simplified model suit to the CRTSⅡ slab ballastless track to make the analysis of the bridge seismic response. Making the analysis of influencing law of the internal forces at the bottom of the pier and the displacement on the top of the pier belong to the bridge structure with the coefficient of friction between the friction plate and the base plate、the stiffness of end-spine、the stiffness of abutment、the stiffness of shear gullet、the height of the pier under the multi earthquake.(4) Analyzing the rationality of the simplified calculation model of the CRTSⅠ、Ⅲ slab ballastless track to make the bridge seismic response. Based on the above, using the response spectrum method to make the analysis of the seismic response effect of the bridge structure with tack constraints and the longitudinal resistance of the fastener under the multi earthquake. In the end, using the nonlinear time history integral method to make the analysis of the seismic response effect of the bridge structure with tack constraints and the longitudinal resistance of the fastener under the rare earthquake.