Then, 



1^ D^p5 = H X (15.2)3 X (0.35)5 



= 0.30 X 3512 X 0.00525 



= 5.53 cm^ . 



From Figure 4-5, for the above-calculated value of CAH/AL)D^P^ and a 

 linear scale of 1:100, K = 5.0. Using this value of K and equation 

 (4-32), the diameter of the 10 percent smaller than stones in the model 

 core material is 



D = ^-^ ^ Q-^ = 025 ft 

 ^m 100 u.u^j 11 . 



The other stones in the model core material would be increased in size 

 in the same proportion. 



Keulegan (1973) has given the following equations for wave trans- 

 mission through model and prototype rubble-mound structures in core 

 materials with a porosity of 0.46. The equations for wave transmission 

 through prototype structures, when Rn > 2000, are 



and 



The corresponding equations for wave transmission through model struc- 

 tures, when 20 < Rn < 2000, are 



r (C("i 



and 



If the relations above are generalized for the effects of porosity, 

 assuming, as suggested by Le Mehaute, that the function of porosity is 

 F(P) = P~^, equations (4- 34a) and (4-36a) become 



-5-(i) 



10.6 VDA 



gd ^j (4-34b) 



225 



