Research on Dynamic Performance of Concrete-filled Steel Tubular Trussed Arch Bridge under Earthquake

摘要

Taking a double span- swallows-type CFST (concrete-filled steel tubular) trussed arch bridge as an engineering example; a spatial finite element analysis model is established to calculate its dynamic characteristic. The seismic responses in different earthquake input directions are calculated based on the elastic dynamic time history method. Results show that: the out-plane stability of the bridge is weaker than that of the in-plane; the torsion resistance ability of the bridge deck is smaller than that of the arch ribs; the axial force-Fx, shear force-Fz and bending moment-My of the bridge are mainly controlled by longitudinal seismic forces, whereas the shear forces-Fy, bending moment-Mz and torque-Mx are mainly controlled by transverse seismic forces; vertical seismic force has a considerable effect on internal forces of the bridge, so it can not be ignored in seismic design.