Failure mechanism of pile foundations in liquefiable soils under seismic loading: status and challenge

The investigation of earthquake damage shows that the pile foundation in liquefiable soils has been severely damaged in many destructive earthquakes. In view of the prominent problem of pile foundation disaster induced by soil liquefaction, many scholars have adopted multiple research methods to explore the earthquake damage mechanism of pile foundation in liquefiable soils, aiming to meet the urgent need of aseismic design of pile foundation in liquefiable soils. And they have obtained fruitful and important research results, revealing the failure modes of pile foundation in liquefiable soils, such as bending failure, buckling failure and settlement failure. This study surveys and analyzes the typical cases of pile foundation earthquake damage in liquefiable soils, and summarizes the manifestations and failure types of pile foundation earthquake damage. On this basis, the paper dissects progress of different earthquake failure mechanisms of pile foundation, and points out the key and difficult points in the current research. Finally, the insufficiency and challenges of seismic research on pile foundation in liquefiable soils are revealed, and the further research directions are given. This work can provide some useful reference for the researchers, and it is beneficial to the development and perfection of seismic theory of pile foundation in liquefiable soils.