Simulation Analysis of the Effects of Liquefaction on Pile Foundations Under Seismic Response

As a widely used structural element in construction projects, pile foundations have been subject to varying degrees of damage during major earthquakes, especially in liquefiable sites. In order to study the effects of liquefaction on pile foundations under seismic conditions, this paper relies on an actual engineering case of the Xiong’an New Area to Beijing Daxing International Airport Express Line. A numerical model of the dynamic response of pile foundations in liquefied sites under seismic actions is established using the finite difference software FLAC3D. A comparative analysis is conducted between liquefied and non-liquefied sites. The results indicate that compared to non-liquefied sites, liquefaction of the site increases the bending moment on the pile shaft, with increased values for both the maximum bending moment and axial force. The main locations where pile damage may occur are determined. Although the influence of liquefaction on the axial force of pile foundations is relatively small, overall, liquefaction has a significant impact on pile foundations, reducing their bearing capacity.