Numerical Study on 3-Dimensional Behavior of a Damaged Pile Foundation during the 1995 Hyogo-ken Nanbu Earthquake

The purpose of this study is to investigate the process of the damage to a pile foundation located on a reclaimed land during the 1995 Hyogo-ken Nanbu earthquake. A 3-dimensional effective stress analysis using a soil-pile-building model was conducted on a damaged building. The five stories building tilted in a northeast direction because of serious damages to the pile foundations. Sand boils and ground settlements due to liquefaction were observed around the building. The simulated results showed that the reclaimed fill layer liquefied during the earthquake, and horizontal displacements of several tens centimeters occurred at the ground surface. The spatial distributions of the damages to piles were discussed through the 3-dimensional simulation. Consequently, the simulated failure direction of piles was associated with the observed direction of building inclination. The simulation qualitatively reproduced that the most serious damage of PHC piles occurred at the northeast footing among the footings located on the building corners