In the Tohoku-Pacific Ocean Earthquake that occurred in 2011, many social infrastructure
facilities suffered significant damage from resulting tsunami. For disaster recovery, bridges are an
important lifeline, and therefore it is necessary to prevent loss of their functionality when a
disaster such as a tsunami occurs. In conventional designs, however, it was not assumed that
bridge girders or other bridge elements would be carried away by tsunami wave forces, and
estimations of tsunami wave force were difficult because no load calculations or design methods
had been established. The authors are working on hydraulic model experiments and
two-dimensional and three-dimensional numerical simulations to clarify the behavior of tsunami
and their wave forces acting on the upper structure of a bridge1-3. This report presents a general
overview.
