2 Test Facility 



Two-dimensional (2-D) physical model tests were conducted in 

 CERC's 150-ft-long by 1.5-ft-wide by 3.0-ft-deep wave tank ("18-in. 

 flume") and 150-ft-long by 3.0-ft-wide by 3.0-ft-deep wave tank ("3-ft 

 flume"). In both flumes, waves were generated by a piston-type wave 

 board powered by an electro-hydraulic pump controlled by a computer- 

 generated signal. The 18-in. flume has an existing 1:30 (V:H) concrete 

 slope starting 60 ft from the wave board; the 3-ft flume has a 1 :20 con- 

 crete slope starting 36 ft from the wave board and extending for 10 ft, fol- 

 lowed by an approximately 1:100 slope. Pre-test conditons of the 18-in. 

 and 3-ft flumes are illustrated in Figures 3 and 4, respectively. The 

 flumes were modified for each test to meet specific profile needs. 



The models were built to a geometrically undistorted linear scale of 

 1 :20 (modeLprototype) for Task A and 1 :30 for Tasks B, C, and the dike 

 study. Based on Froude's model law (Stevens et al. 1942), the following 

 model-to-prototype relationships were derived. Dimensions are in terms 

 of length L and time T. 



Characteristic 



Dimension 



Model-to-Prototype Scale Relation 





1:20 



1:30 



Length 



L 



Lr 



1:20 



1:30 



Area 



L' 



Ar = {Lrf 



1:400 



1:900 



Volume 



L' 



Vr = {Lrf 



1:8,000 



1:27,000 



Time 



T 



Tr = {Lr)''' 



1 :4.472 



1:5.477 



Water that overtopped the seawalls during physical model tests was 

 pumped into a rectangular catch basin at the conclusion of the test run. 

 The change in elevation of water in the catch basin was then measured 

 with a point gauge and converted to prototype overtopping rate in cubic 

 feet per second per linear foot of prototype seawall (cfs/ft) by the follow- 

 ing relationship: 



Cliapter 2 Test Facility 



