Shaking table tests on a deep-water high-pier whole bridge under joint earthquake, wave and current action

Abstract

The deep-water high-pier bridges that located in active seismicity areas have the potential to be suffered for earthquakes, wave and current action synchronously during construction and service period. In order to investigate the dynamic responses of the whole bridge piers under joint earthquakes, waves and current action. This paper is based on a deep-water high-pier whole bridge as a prototype, pursuant to the elastic similarity law, the shaking table test under the joint action of an earthquake, wave and current is carried out for a 1:220 geometric scale model. At different water levels, a white noise test and independent earthquake action, joint wave and current action, and joint earthquake, wave and current action were carried out. The test research found that the presence of water decreases the natural frequency of the piers. The effect of water on the higher-order frequencies are greater than those of the low-order frequencies. The dynamic amplification factors of bridge piers in water are greater than those without water, but the effect of the water level is decreases exceed a certain water level. Earthquakes have a great influence on dynamic amplification factors and strains, and the waves and current have a greater influence on hydrodynamic pressures. Earthquakes, waves, and current have an influence on the bridge, but the dominant is earthquakes. The influence of the waves and current on the bridge can not be ignored. The peak strains and peak hydrodynamic pressures under joint earthquake, wave and current action are evaluated to the peak strains and peak hydrodynamic pressures under superimposed independent earthquake, independent wave and current action. It can be seen that the joint effect is not a simple superposition effect. There are complex interactions between the earthquake, wave and current. Considering the effects of coupling, the whole bridge is more complex than a single pier, and the dynamic responses are complicated. Therefore, it is essential to investigate the joint action of earthquakes, wave and current in bridge design under complex circumstances.