PART II: MODEL DESIGN AND SETUP 



Test Facilities 



2-D tests 



5. All tests were conducted in concrete flumes equipped with vertical 

 displacement, monochromatic wave generators. Toe buttressing stone sections 

 were tested in a 5-ft-wide* flume (Figure 1), while four toe berm stone 

 sections were tested simultaneously in 5- and 6.75-ft-wide flumes that share a 

 common generator (Figure 2) . Two toe berm test sections were constructed 

 adjacent to one another in each of the flumes (Photo 1). 



3-D tests 



6. A majority of the tests were conducted in an L- shaped wave basin 

 which has overall dimensions of 250 ft long and 50 and 80 ft wide at the top 

 and bottom of the L, respectively, and 4.5 ft deep in the test area (Fig- 

 ure 3). The L-shaped basin was equipped with a flap wave generator, and mono- 

 chromatic waves were generated for these tests. 



7. Some of the tests were conducted in a T-shaped wave basin 164 ft 

 long, 43 and 15 ft wide at top and bottom of the T, respectively, and 3.3 ft 

 deep (Figure 4) . The basin was equipped with a horizontal displacement wave 

 generator capable of making both monochromatic and spectral waves. 



Test Facility Calibration 



8. Prior to construction of the test sections, each test facility was 

 calibrated for a range of incident wave conditions and water depths. This is 

 the preferred method of calibration because it eliminates the influence of 

 reflected waves from the structure so that wave conditions match the design 

 conditions (defined through prototype wave gaging and/or hindcasting done 

 prior to prototype design and construction) . Changes in model water surface 

 elevations as a function of time, i.e., wave heights, were measured by 

 electrical parallel resistance or capacitance wave gages. Wave gages, or gage 

 arrays in the case of spectral wave conditions, were placed in each of the 

 test facilities at the approximate location where the sea-side toe of the 



* A table of factors for converting non-SI units of measurement to SI 

 (metric) units is presented on page 3. 



