Non-linear Seismic Response of CFST Arch Bridge Considering Foundation-structure Interaction

The linear and non-linear seismic responses of deck type long span concrete filled steel tube(CFST) arch bridge were analyzed considering foundation-structure interaction.Taking a deck type CFST arch bridge as studying object,a 3D viscoelastic artificial boundary was constructed to simulate the radiation damping and the elasticity recovery capacity of the medium at the far field,and the whole analytic model including the foundation and arch bridge was established.Inputting the Qian'an seismic wave which has amax=0.2g amplitude,the linear and nonlinear seismic responses of deck type long-span CFST arch bridge were analyzed considering foundation-structure interaction.The result shows that(1) the nonlinear influences are not ignorable when analyzing the bridge seismic response displacement,the displacement and bending moments My and Mz of main arch ribs of nonlinear seismic response are bigger than those of linear seismic response analysis;(2)the lower chord axial force at springer of nonlinear seismic response analysis is a bit bigger than that of linear seismic response analysis,the lower chord axial force at mid-span of nonlinear seismic response analysis is less than that of linear seismic response analysis.