低天端型人工リーフの透過特性

抄録

This paper presents the result of hydraulic model experiments on the coefficients of wave transmission over a low-crown-height type artificial reef which is made of wave dissipating concrete blocks. The ratio between the depth from water surface to the top of the submerged reef and the incident wave height, R/H_I, varies from 0.79 to 8.75. The relative width of the reef against wave length, B/L has a variation from 0.51 to 2.53. The wave-breaking limit, R/H_I, lies between 0.8 and 1.3 for the above structure. The transmission coefficient, K_T, decreases following an increase in B/L. The change of K_T is small for a range of B/L larger than 1.6. With regard to the relationship between the ratio of wave height over block scale, H_I/d′, and K_T, K_T decreases slightly parallel with increase in H_I/d′, being proportional to increase in B/L. There is no significant relationship identified between Reynolds number, Re, and K_T. Based on the above results, an empirical formula to assess K_T is proposed, employing B/L as a parameter.