Abstract
This paper is intended to clarify the seismic response characteristics of the caisson-pier during earthquakes by use of observed results. The main obtained results are as following: 1) the (acceleration) response of pier depends on the epicentral distance, and is dominated by the contribution of higher mode when the epicentral distance is short. 2) the frequency characteristics of caisson and pier are almost similar to those of the basement and the superstructure respectively. 3) the time-dependent property of the frequency characteristics in the response of caisson and pier appears when the frequency of acceleration of the basement is time-dependent.
