ABSTRACT
ABSTRACT: Field performance of various pile foundations in the 1995 Hyogoken-Nambu earthquake have been compiled and summarized, together with their failure and deformation modes identified by field investigation including surveys using borehole cameras and/or slope-indicators. It has shown that:(1) In the nonliquefied area where damage to superstructures concentrated, quite a few buildings tilted with their superstructures remaining intact, due to shear failure of their pile heads; (2) In the liquefied area, many buildings supported on non-ductile piles suffered foundation distress with their superstructures remaining intact, due to failures of the piles at the interface between liquefied and non-liquefied layers; and (3) In the laterally spreading area, similar but more extensive foundation distress occurred in which the piles of a building near the waterfront often showed different failure modes in the direction perpendicular to the waterfront, while those away from the waterfront showed similar deformation patterns. The significant difference in damage pattern of piles among non-liquefied, liquefied, and laterally spreading areas is mainly due to the difference in inertial and kinematic effects between the three areas as well as the difference in spatial variation of ground displacement in the laterally spreading area.
