Mechanisms for Damage and Failure from the Great East Japan Tsunami - Tohoku, Japan Earthquake and Tsunami of 2011 - page 48

Figures 19 - 22 show examples of structures that withstood wave runup and
overtopping.

Figure 19. Arahama Beach shoreline
dike — Minor damage to top
pavement/backside concrete slope; scour
on landward side of dike

Figure 20. Naruse River north entrance
jetty — Damage to a small section of the
river revetment, as indicated by the work
crane; no damage to the jetty itself

Figure 21. Taro tsunami wall — No
substantial damage to section shown

Figure 22. Shizugawa, fishing port
bridge — No damage observed

3.2 Tsunami Overtopping with Structural Damage or Failure
Tsunami wave runup and overtopping that cause structural damage and even failure
typically result from hydrostatic and hydrodynamic loads that
(a) Exceed the structure's design capacity (shear stresses and/or bending stresses
exceeding design limits of the structure's members)
(b) Scour the landward and/or seaward sides of the structure, or its end points,
resulting in failure due to loss in foundation earth support
(c) Produce excessive turbulent and supercritical flows resulting in failure