This paper aims at proposing the method to evaluate the seismic coefficient of caisson type and sheet pile type quay walls against the level-one earthquake ground motion. The proposed method takes the frequency characteristic and the effect of duration time of earthquake ground motion into consideration. We conducted two-dimensional earthquake response analyses and showed that the proposed method well evaluates the seismic coefficients to be applied to the design of the quay walls within the displacement range of 5 to 20 cm.
