Research on Seismic Simplified Analysis Method Under Rare Earthquake Continuous Rigid Frame Bridge with Qualified CFST Stack

Based on the Labajin Bridge, this paper uses Midas civil finite element software to establish a calculation model for the high-dose continuous rigid frame bridge with qualified CFST stack. Taking the height of the pier, the slope of the laced pier and the steel content of the column and limb as the design parameters, the calculation model of 40 different periods is constructed, and the high-dose continuous rigid frame bridge with qualified concrete-filled steel tube stacks under the rare earthquake The elastic and elastoplastic time-history analysis is carried out. By comparing the displacement and bending moment time-history curves of the control section, it is found that the vibration modes of the two different analysis methods are more consistent. Based on this, the seismic simplification method of the bridge is studied. Using the statistical induction method, the relationship between the control section displacement, the bending moment adjustment coefficient and the structural period is obtained by fitting, and the equivalent elastic method is proposed. The algorithm is verified by different seismic waves, fortification intensity and acceleration peak. The results show that the proposed equivalent elastic method agrees well with the elastoplastic method. The research results can effectively improve the computational efficiency of seismic design, and also provide reference and reference for the seismic design specifications of such structural systems.