Abstract:A six-span extradosed cable-stayed bridge with a single cable plane was investigated in this study to assess the influence of wave traveling effect on the earthquake response of multispan extradosed cable-stayed bridges. A finite element model of the full bridge was established using the software MIDAS/Civil, and the multi-point excitation behavior was simulated based on the theory of relative motion. The internal force or displacement response of three key positions, namely pier bottom, tower bottom, and tower top, under multipoint ground motion excitation were analyzed. Furthermore, the variation law of structural internal force and displacement under different apparent wave velocities was also explored. The research results reveal that the traveling wave excitation has a significant effect on the earthquake response of the multispan extradosed cable-stayed bridge. At an apparent wave velocity of 500 m/s, the internal forces or displacements at the most unfavorable key position are approximately 1.2 times those under uniform excitation. Furthermore, traveling wave excitation has adverse effects on the bending moment and shear force at the bottom of the middle pier and side tower, as well as on the displacement at the top of the side tower. As the apparent wave velocity increases, the influence of traveling wave excitation gradually weakens. When the apparent wave velocity exceeds 7000 m/s, the internal forces and displacements at key positions are basically the same as those under uniform excitation. This finding indicates that the influence of traveling wave excitation on the internal force at key positions of the structure can thus be ignored.
