Stability of Breakwaters Against Tsunami Attack

Despite the regularity with which tsunami waves attack a variety of countries around the world, comparatively little attention has been paid in the past to the design of tsunami-resilient breakwaters. This chapter will highlight some of the problems related to the failure mechanisms of caisson and armored caisson breakwaters against tsunami attack, focusing mainly on two modes: bearing capacity failure at the heel of the caisson and the stability of primary armor units. A methodology for the design of such armor will be provided for the case of overtopping waves, based on real life analysis of the failure of such armor. This method takes into account not only the tsunami level and height, but also the function of the structure (in terms of the importance of what it has been designed to protect), highlighting the need for an approach that can minimize the cost of such countermeasures.