(b) Wave Run-up 



A report entitled "Wave Run-up on Roughened and Permeable Slopes" 

 was published by the American Society of Civil Engineers. This report 

 indicates the effect of roughness and permeability on wave run-up on 

 slopes. As might be expected, the data show that both slope roughness 

 and permeability reduce wave run-up considerably below that observed 

 for smooth slopes, the degree of reduction decreasing with both rough- 

 ness and permeability. A number of large scale tests involving waves 

 up to 5 feet in height were made to determine whether or not model 

 scale affected values of wave run-up obtained. These tests were made 

 on slopes of 1 on 3 and 1 on 6 . The data are now being analyzed; the 

 preliminary analysis indicates that a scale effect does exist. Wave 

 run-up values for the large-scale tests were higher by about 10 to 157o, 

 and wave overtopping values were higher by 25% on an average. These 

 tests were made with a smooth board slope in which the roughness of 

 the slope was essentially the same as that in the small-scale labo- 

 ratory tests. To better scale up the roughness from that of the smaller 

 scale tests, a very few tests were made with a single layer of sand 

 glued to the larger scale slope. This sand roughness reduced the run- 

 up somewhat below that observed on the smooth slope, but the reduction 

 was not great enough to bring these run-up values in line with those 

 determined at small scale. A report "Run-up on Composite Slopes" was 

 presented at the 6th Coastal Engineering Conference. This report 

 presents methods of determining run-up for structures of any variable 

 slope based on run-up data for smooth slopes. 



(c) Study of Sand By-passing Operations 



As a continuation of the observational program, a survey of the 

 Port Hueneme area was made in June 1958. These data together with the 

 earlier data are now being analyzed. Consideration. is being given to 

 use of an adapted (radioactive) density gage and a velocity meter for 

 use on by-pass operations to determine quantity and rate of pumping. 



(d) Laboratory Study of Effects on a Groin Field on the Littoral 

 Drift Passing the Field 



The new trapping and sand-moving system using eductors to transfer 

 the trapped sand to a weighing basin in the feeder beach area was 

 tested, and has proved very satisfactory. Tests were made involving a 

 low short groin, a high short groin, and a high long groin. Tests are 

 now being continued. Tests are also being initiated to study the move- 

 ment of sand along a steeper beach. The initial tests have been made 

 on a 1 to 20 slope, and tests now are being made also on a 1 to 10 

 slope in an adjacent wave basin. Preliminary results indicate that the 

 rate of movement along the steeper slope is 2 to 3 times that along the 

 1 on 20 slope with the same wave conditions. 



(e) Measurement of Suspended Material in Laboratory Wave Tanks 

 Additional sampling has been carried out, and the data are being 



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