Shaking table test verification of traveling wave resonance in seismic response of pile-soil-cable-stayed bridge under non-uniform sine wave excitation

Abstract

The traveling wave resonance phenomenon exhibits in the seismic response of the symmetric bridge structure. However, there is a scarcity of shaking table tests validating the traveling wave resonance. A 1/70-scale pile-soil-cable-stayed bridge model was fabricated following the preliminary design of a cable-stayed bridge with a main span of 1400 m. Shaking table tests were performed to verify the traveling wave and mode shape resonances in the seismic response of the bridge model when separately subjected to two specific sine waves longitudinally. The vertical acceleration frequency spectra and seismic response of the bridge model were compared between uniform and non-uniform sine wave excitation. The results showed that the traveling wave and mode shape resonances were examined in the seismic response of the pile-soil-cable-stayed bridge model under non-uniform excitation of the specific sine waves. The traveling wave excitation increased the symmetric response at the symmetric girder location but decreased the antisymmetric responses of the towers and girder, compared to the uniform excitation regarded as antisymmetric input. Finally, a finite element model was developed in OpenSees that could capture the seismic response changes caused by the traveling wave effects of the specific sine waves and proximately reproduce the experimental results. Therefore, the traveling wave and mode shape resonances were verified by the numerical simulations.