Dynamic response of long-span continuous curved box girder bridge under seismic excitation

Abstract

Form function matrix is created by introducing high order displacement interpolation function in the node. Based on the virtual work principle and dynamic finite element theory, the spatial element stiffness matrix, mass matrix and earthquake mass matrix of a thin-walled box girder having 9 freedom degrees at each node are deduced. The D’Alembert vibration equation is also established. Newmark-β method is used through MATLAB to solve the seismic response of a long-span continuous curved box girder bridge under El-centro seismic waves. Meanwhile the spatial finite element model of the whole bridge is established by ANSYS. The results indicate that the dynamic responses of pier columns exhibit spatiality. The dynamic response of a bridge structure under 2D coupling horizontal seismic excitation is much bigger than that under 1D horizontal seismic excitation. The critical angle of seismic waves is 50° for radial displacement response. Theoretical calculation results are in agreement with the finite element analysis results. The deduced element matrix not only can be used to calculate the seismic response of long-span curved beam bridge structures but also can provide significant references for the structures in vibration response caused by moving traffic.