In the current design of port and harbour structures, Seismic Coefficient Method is used to analyze the seismic effects. The Method is based on the assumption that the maximum seismic force acts statically on structures. But apparently, actual seismic force does not act statically.
　Therefore it is very essential to check whether this Method explains the real situation accurately enough from the point of facility design.
　In this report, the presetnt earthquake-proof design method is studiing, analyzed the stability of port and harbour structures damaged by the 1978 Miyaghi-Ken-Oki Earthquake.