Shaking table test on seismic response of pile groups of bridges in liquefiable ground

Shaking table test on seismic low-cap pile groups-soil-bridge structure interaction in liquefiable ground with the overlying clay layer and the lower saturated sand layer is completed. The test indicates that pore pressure caused by the slight vibration during earthquake is only a small amount of accumulation, and pore pressure accumulation mainly occurs at the stage of strong vibration. The pore pressure gradually increases as the input motion amplitude becomes larger and the shaking duration becomes longer. It’s obtained that the strongest liquefaction lags behind the peak acceleration time. Acceleration of the sand is remarkably influenced by soil liquefaction. With the development of soil liquefaction, the time-delay characteristics between the peak soil displacement time and the peak input motion time, and the peak acceleration time of soil are significantly displayed, and soil displacement plays an increasingly prominent role in the bending moment of the pile. Similarly, the displacement of liquefied sand has a specially obvious effect on pile-soil interaction. The fully liquefied sand doesn’t completely lose the bearing capacity. Whether the sand is liquefied or not, the acceleration law of the pile and the sand maintains consistent. During the earthquake, the jump reaction of the acceleration and the bending moment on the pile is observed near the soil interface. It’s no doubt that the shaking table test provides the necessary groundwork to study seismic performance of pile groups of bridges.