ABSTRACT
Pile foundations are widely used to support structures over ground that has inadequate bearing capacity. In seismically active areas with saturated soils, the performance of pile foundations is a complex problem owing to the effects of the progressive buildup of pore water pressure in the soil during earthquake loading. With the increase in pore water pressure, soil stiffness and strength is degraded, and the ability of the soil deposit to support foundations rapidly decreases, leading to soil liquefaction, which is the extreme manifestation of the pore water pressure increase in saturated soils during earthquake loading. The significance of soil-liquefaction-related damage to pile foundations has been clearly demonstrated by major earthquakes, such as those at Niigata in 1964, Loma-Prieta in 1989, Kobe in 1995 and Manzanillo in 1995. Hence the prediction of pile behavior in liquefying soils under earthquake loading is an important issue in the design of pile foundations designed for seismically active regions.
