Dynamic Response of Saturated Sandy Foundation and Friction Pile under Seismic Action

Karst landform poses a great challenge to the deep foundation construction of bridges. However, there is little report on the dynamic response of piles under seismic action in karst area. To make up for the gap, this paper mainly explores the pile-soil interaction of saturated sandy foundation under seismic effect. Taking friction pile and saturated sandy foundation as the objects, the authors carried out shaking table tests on how the waveform and peak acceleration of seismic waves affect pore pressure and acceleration response of the soil around the pile. Further, the peak strain distribution of the friction pile was investigated under different sandy foundation conditions. The results show that the pore pressure of saturated sand around the pile first increases rapidly, then stabilizes, and later declines slowly under seismic action; the peak acceleration of saturated sand is negatively correlated with vertical depth; the change of acceleration increases with the proximity to the pile; the earthquake has a dramatic impact on the pile surrounded by saturated sand, i.e. the saturated sandy foundation weakens the seismic resistance of the pile; the peak strain of friction pile is smaller in the middle and greater at the ends; under the same seismic wave, the strain response of the friction pile surrounded by saturated sand is greater than that of the pile surrounded by dry sand. The research results provide a good reference for deep foundation construction in karst area. © 2020 WITPress. All rights reserved.