Time history analysis of seismic response of through CFST non isolated and isolated arch bridges

Abstract

To explore the difference in the impact of transverse bracing on the seismic effect of through concrete-filled steel tube arch bridges with non-isolated and earthquake-isolated, nine non-isolated and earthquake-isolated structural models under different cross-bracing arrangements were established, and Elcentro seismic waves were selected. The internal force, displacement, velocity, absolute acceleration, relative acceleration, and separation of arch ribs of each model were compared and analyzed under uniform excitation along the bridge, transverse and vertical directions, multi-dimensional combined excitation, and multipoint excitation considering the traveling wave effect. Based on the shear force and displacement of the earthquake support, it is concluded that the internal force response of different excitations of various models is more complicated. The installation of transverse bracing on the upper part of the arch rib can reduce the vertical displacement of the arch rib of the nonseismic structure. The “X”-shaped cross brace at the top of the arch rib and the “K”-shaped cross brace at the lower part help to reduce the transverse acceleration of the arch rib. The absolute acceleration and relative acceleration of the seismic structure arch ribs are significantly reduced.