Seismic Responses and Collapse of a RC Pedestrian Cable-Stayed Bridge: Shake Table Tests

Abstract

There have been numerous experimental studies on the seismic collapse of reinforced concrete (RC) buildings and RC girder bridges, but not on the seismic collapse of RC pedestrian cable-stayed bridges. Postearthquake field investigations revealed that if RC pedestrian cable-stayed bridges in seismic regions were not appropriately designed, they are likely to encounter severe damage or collapse. This paper thus presents an experimental investigation on a 1:12 scaled RC pedestrian cable-stayed bridge to explore the seismic behavior and collapse mechanism of the bridge under different levels of ground motion. The design, construction, and installation of the bridge, along with the shake table tests, were performed. The dynamic characteristic tests of the bridge were carried out, with the natural periods and mode shapes identified. The bridge was then tested by subjecting it to three levels of ground motion, i.e. small, moderate and large earthquakes. The seismic behavior and seismic-resistant capacity of the cable-stayed bridge were finally assessed at the component level and the failure mode of the bridge was identified based on the seismic responses recorded by the measurement system. The test results showed that the collapse of the RC pedestrian cable-stayed bridge was triggered from the flexure failure of its columns and ended with the flexure-shear failure of its tower.