Abstract
There had been very few records on damages of steel pile type piers in previous earthquakes. However, several piers located in front of gravity caissons were damaged during the 1995 Hyogoken-Nambu Earthquake. Damage of piles at the site suggested that the lateral flow of the ground might accelerate the failure of the pier. In this study, centrifuge tests were firstly carried out to simulate dynamic behavior and failure of a steel pile type pier damaged in 1995 Hyogoken-Nambu Earthquake. And also some tests with different ground conditions were conducted to discuss the effects of liquefaction of the sand layer under the rubble mound on the lateral flow of the ground and the effect of the approaching plate connecting gravity caisson to ther pier on the dynamic interaction between the two structures.
