Abstract
The serious damage of coastal dikes and breakwaters occurred in the tsunami caused by the 2011 off the Pacific coast of Tohoku earthquake. It is important to reinforce these coastal structures with the concrete blocks and to give the function of tenacious structures. Hydrodynamic experiments had been performed to study the damage of concrete blocks armoring on slope and mound in the side of land of these coastal structures for the over flow in tsunami. In the case of coastal dikes, the stability of concrete blocks and the damage of these coastal structures are affected by the strength of foundation in spillway. The stability of blocks are also affected by the types of blocks and there geometrical arrangement. In the case of breakwater, the critical values of the total head above the crest of breakwater, in which the damage of concrete blocks occurs, are affected by the height of breakwater above the still water level and the water depth from still water level to the foundation of breakwater. The positions where the damage of armor concrete blocks occur on the foundation change with the total head above the crest of breakwater.
