Damage to Coastal Structures by Tsunami-Induced Currents in the Past

Examples of damages to coastal structures caused by tsunami-induced current are collected from documents in Japan, and classified into four types. Soil embankments near underpasses or bridge abutments are eroded by concentrating water current. Currents parallel to long structures can develop strongly enough to scour the structures toe and destroy them. Embankments made of soil are easily eroded by overflowing water of tsunamis. The toe of quay walls is unprotected against the waterfall that occurs when landed water returns and hits the nearly exposed sea bottom as tsunamis recede.