Seismic Response Analysis Of A Through Concrete-filled Steel Tubular Arch Bridge

Concrete filled steel tube arch bridge finds favor in bridge engineers' eyes because of its good,performance with external loads as well as its new and beautiful structural style.Stress in Concrete filled steel tube arch bridge is comparatively complex,the aseismic problems of long span concrete filled steel tube arch bridge need further research.This paper takes Nanhe super bridge as the engineering background,specific work of this paper in the following areas:(1)This paper introduces the simulation method of pile-soil effect based on elastic node support,and finally solves the stiffness of soil of Nanhe super bridge.The spatial model considering the pile-soil interaction condition is established.The eigenvalue analysis is used to solve the natural frequency and vibration mode of the bridge.(2)According to the principle of selecting wave and adjusting the three selected seismic waves,the longitudinal and three-dimensional seismic input is used to calculate the displacement and internal force of the control section of the arch rib under the action of the Nanhe super bridge by the time history analysis method,the results are compared with the response spectrum and presented in the form of a line graphs.(3)This section re-divides the pile unit and recalculates the stiffness value of the soil spring,and the establishment of the simulation model under the space model.This section calculates the response from the longitudinal input and the three-dimensional seismic input,and the results of the two schemes are compared and analyzed,which shows that the simplified method is to meet the precision requirement.Taking into account the impact of several factors such as seismic input angle,damping ratio and pile bottom simulation on bridge seismic response.(4)In this chapter,the pushover analysis is used to analyze the model.This section considers the effect of the acceleration constant loading mode and the normalized mode on the performance point solution.The pushover curve in the X-direction and Y-direction of the piers is drawn.The pushover curve is converted to the demand spectrum by the formula,and the performance points in both directions are calculated.Using the current seismic code to solve the vertical and horizontal direction of the allowable displacement,so as to the South River Bridge piers to judge the seismic performance.