The field performance of various pile foundations that experienced lateral ground spreading during past earthquakes is summarized. It is shown that: (1) damage concentrated near the top and bottom of the liquefied layer of non-ductile piles, leading to the tilt of their superstructures in many cases; (2) the piles within a building near the waterfront show different failure modes in the direction perpendicular to the waterfront, while those away from the waterfront show similar deformation patterns; (3) pile foundations enclosed by cement mixing walls, disphragm walls, and cement column walls did not suffer any vital damage; and (4) the arth pressures acting on rigid foundations from non-liquefied crusts overlying laterally spreading soils many be as large as the passive ones, whereas those acting on deformable foundations appear considerably smaller. A pseudo-static analysis is conducted for well-documented case histories of pile foundations to estimate the scaling factors for p-y springs of laterally spreading soils. The analytical results show that both the coefficient of the horizontal subgrade reactions of piles and the maximum reaction force of laterally-spreading soils are 0.05-0.2 times those of non-liquefied soils.
展开▼
