In order to take an earthquake disaste preparedness effectively, it is necessary to estimate the earthquake damage deformation and cost following the earthquake stability judgement of port facilities. In this report it was discussed to estimate the earthquake damage deformation and cost of gravity type qualywalls and sheet pile quaywalls based on earthquake damage records which contain 679 earthquake damage data of port facilities. The analyzed resutls are shown under.
(1) The ratio of the seismic coefficient corresponding to the ground acceleration versus the destructive seismic coefficient which fix the limit of the seismic stability of the structures was defined a seismic safety factor. The regression equations between the seismic safety factor and the earthquake damage deformation and cost were used for the estimation of the earthquake damage deformation and cost.
(2) The seismic coefficient for design which show minimum value of the sum of the estimated earthquake damage cost and construction cost by the increase of the seismic coefficient were calculated for the gravity type quaywalls and sheet pile quaywalls as an example.