7b . The design breaking wave height was selected as the wave height at which 

 H/h equaled y b . 



108. Once estimates of h t and h c were determined by the above- 

 described procedure, the horizontal location of the bar was known, and the 

 size of the bar could be determined. The depth at the bar trough served as a 

 point of origin from which the shoreward face length was calculated from the 

 given value of /2 3 and the vertical distance between h and h t . After 

 the shoreward bar face was calculated, the horizontal location of h c was 

 known, and the seaward bar face length could be determined for the given 

 seaward angle . 



Test Procedure 



109. The bar was placed in the tank at the calculated crest depth. 

 Since h c was based on an estimate of breaking wave height, waves were 

 generated, and the actual breaking wave height was measured. The location of 

 the bar was then adjusted to the correct h c if necessary. Adjustments to 

 correct h c were typically less than 0.05 ft vertically, and the maximum 

 deviation from the calculated value was 0.07 ft. 



110. Water surface elevations were measured with the gages sampling at 

 10 Hz, from which statistical and spectrally defined wave parameters could be 

 calculated. Wave breaking was recorded on videotape. Runup was also measured 

 for each test by visually observing the maximum horizontal distance of the 

 leading edge of the water past the shoreline for 12 or more successive waves, 

 and then converting the distance to vertical elevation above SWL. Qualitative 

 observations were made of the surf zone. Included in the experiment logbook 

 were the depth of bubble penetration at the surf zone gages and the wave form 

 (reformed wave or bore) . If the broken wave reformed, the horizontal location 

 of reformation was recorded. Additional notes consisted of the horizontal 

 locations of the gages and water depths at the gages; horizontal location of 

 the bar and water depth at the trough, crest, and toe of the bar; and the 

 water temperature during the test. 



111. Once a test was completed, the seaward face of the bar was 

 replaced to give a new £ x . Wave height, wave period, and shoreward bar 

 angle were held constant, and the newly constructed bar was placed in the tank 

 for the next test. The preceding method was repeated until tests were made 



70 



