PROPOSAL AND APPLICATION OF EXTENSION STRUCTURE FOR PROTECTING BREAKWATER ARMOR BLOCK AND MOUND

Abstract

 The armor blocks expected to keep stability of the coastal structure from tsunami overtopping wave forces may have serious damages by high wave condition that occurs seasonally. To mitigate the overtopping wave forces to the armor blocks, adjustment of position of fall of the overtopping wave is supposed to be effective. A serial laboratory experiments was carried out to estimate the effect quantitatively. In case of non dimensional values of falling position and water depth are larger than 1.3 and 0.8 respectively, the armor blocks keep stability.

 Numerical simulation by high precision particle method shows good agreement with laboratory experiments. And, we confirmed formation of large swirl and the flow of water within the structure that could not be confirmed in the experiments.

 And then, we confirmed that the breakwater with porous structure further increases the stability numerically and experimentally.