PART II: THE MODEL 



Design of Model 



4. Tests were conducted at an undistorted linear scale of 1:28.5, model 

 to prototype. Scale selection was based on the size of model dolosse and 

 armor stone available relative to the size of the proposed prototype dolosse 

 and armor stone, elimination of stability scale effects,* and capabilities of 

 the available test flume. Based on Froude's model law** and the linear scale 

 of 1:28.5, the following model-to-prototype relations were derived (dimensions 

 are in terms of length (L) and time (T)): 









Model-Prototype Scale 



Character 



istic 



Dimension 

 L 



Relations 



Length 



L r = 1:28.5 



Area 





L 2 



A r = L 2 = 1:812.3 



Volume 





L 3 



V r = L^ = 1:23,149.1 



Time 





T 



T r = Lj /2 = 1:5.3 



5. The specific weights of the model construction materials differed 

 from their prototype counterparts; therefore sizing of the model construction 

 materials was based on the following transference equation: 



\ 7m _ \ /m / m 



U 





- 1 



where 



subscripts m, p = model and prototype quantities, respectively 



<a 



Y = specific weight of an individual armor unit or 

 stone, pcf 



L m /L = linear scale of the model 



* R. Y. Hudson. 1975 (Jun). "Reliability of Rubble-Mound Breakwater 

 Stability Models," Miscellaneous Paper H-75-5, US army Engineer waterways 

 Experiment Station, Vicksburg, Miss. 

 ** J. C. Stevens et al . 1942. "Hydraulic Models," Manual on Engineering 

 Practices Mo. 25, American Society of Civil Engineers, Mew York. 



