Experimental Study on Effect of Water Depth on Earthquake Response of a Deep-water Cable-stayed Bridge Tower

Abstract With the aim of investigating the effect of water depth on the earthquake response of a deep-water cable-stayed bridge tower, this study designed and manufactured a large-scale bridge tower model, taking a cable-stayed bridge across a deep reservoir of a hydropower station as a reference. Under the boundary conditions similar to the reference, shaking table tests were conducted to reflect the structural response of the bridge tower under white noise and earthquake actions at different water depths. The time history curve of the bridge tower’s structural response was recorded and used to investigate the variations in the natural frequency, displacement, stress and strain of a deep-water cable-stayed bridge tower at different water depths under earthquake actions. The results showed that the natural frequency of the bridge tower decreased almost linearly with the increase in the water depth. The displacement at the tower top increased gradually with the increase in the water depth under earthquake actions. In addition, the stress and strain at the tower bottom increased almost linearly in the transverse direction and nonlinearly in the longitudinal direction with the increase in the water depth.