Study On Static Dynamic Analysis Of Railway Through Concrete Filled Steel Tube Tied Arch Bridge

Concrete filled steel tube(CFST) arch bridge has been widely used in practical projects of highways and railways with features of high bearing capacity, strong span capacity, good seismic performance, and convenient for construction. Since force situation in the construction of CFST arch bridge is relatively complicated, moreover, there are no related specifications and regulations at home and abroad, it becomes necessary to research its structural features and mechanical characteristics.Taking Haiqing Railway 80m-CFST arch bridge as the object of research, this paper established the full-bridge structure space calculation model by finite element analysis software Midas Civil, analyzed static and dynamic characteristics, and finally obtained mechanical characteristics and displacement characteristics of main girder and arch rib, and dynamic characteristics of the bridge, thus provided a reference for similar long-span CFST arch bridge project in the future. The research contents of this paper mainly include the following three aspects:1. Analysis of static characteristics. This part built full-bridge structure space calculation model by Midas Civil, analyzed static characteristics in all construction stages of Haiqing Railway 80m-CFST arch bridge, including mechanical characteristics and displacement features of box girder and arch rib, and pointed out that the impacts that CFST arch bridge suffered in different construction stages should be taken into full consideration; this part also conducted stress monitoring of box girder and arch rib, and obtained that this CFST arch bridge is safe in all construction stage by comparing measured values and theoretical values.2. Analysis of self-vibration character. This part built a dynamic model, obtained self-vibration frequency of this bridge and mode of vibration in all construction stages through modal analysis, and concluded that the horizontal stiffness of this bridge is less than the vertical stiffness.3. Response spectrum analysis. This part built dynamic model for response spectrum, and respectively obtained internal forces and displacement responses of thebridge under actions of six working conditions, i.e. horizontal seismic input, lengthways seismic input, vertical seismic input and combinations of the three seismic inputs.