This paper describes the performance of pile foundations in liquefied soils. Two different aspects of pile response are considered, seismic response to earthquake shaking and response to lateral spreading when the liquefied ground is sloping. The case histories show that piles can be designed economically to resist large lateral displacements and that most of the reported examples of damage from lateral spreading involve weak piles with little reinforcement which were installed to control vertical settlements and were not designed to be moment resistant. A quasi-3-D continuum method is presented for dynamic effective stress response analysis of pile groups in liquefiable soils. The method is validated using data from centrifuge tests. Methods are presented also for the analysis of piles due to lateral spreading
