Shaking table test for seismic interaction of pile groups-soil-bridge structure with elevated cap in liquefiable ground

Using a pile group supported bridge structure model with elevated cap and single column pier, a shaking table test was performed to study seismic pile groups-soil-bridge structure interaction and to reproduce the macro-phenomena of soil liquefaction and destruction on piles in liquefiable ground during earthquake. The acceleration and pore pressure of liquefiable ground, acceleration, displacement and strain response of the pile group-column pier-superstructure system were monitored during the test. The results indicate that the input acceleration amplitude and burial depth are the important factors which affect pore pressure of sandy layer. Acceleration response of sand layer from bottom to top appears to transform from gradual weakening to gradual magnification with the development of ground liquefaction. The seismic response of elevated cap pile foundation is closely related to the properties of soil layer amplitude of input earthquake motion and the level of ground liquefaction. The system is prone to collapse as a result of strong liquefaction under seismic effect.