and stability was continued. Application was made to data gathered a 

 number of years ago in the area of Mission Bay, California, but the 

 small range of data and the lack of precision inherent in some of the 

 data presented considerable difficulty. Results to date, however, tend 

 to confirm that wave height and period are important factors which 

 influence beach slope. 



VII. Beach Erosion Board Laboratory . 



(a) Wave Forces on Structures. 



Analysis was continued of the wave force data obtained in the large 

 wave tank on a vertical 12-inch diameter pile. This work has been 

 pointed particularly toward the phase relationship of the water elevation, 

 water velocity, and wave force with the passage of the waves. A report 

 on this work is under preparation. 



(b) Wave Run-up. 



Additional large scale data involving waves up to 3-1/2 feet in 

 height were gathered on a 1 on 1-1/2 riprap protected slope using 160- 

 pound rock in an attempt to determine possible existence of a scale 

 effect. Final analysis of these data is awaiting calibration of the 

 wave tank, and accurate determination of the wave height at the structure, 

 with the structure not in place. The wave run-up data presented by Hudson 

 in his article "Laboratory Investigation of Rubble Mound Breakwaters", 

 published by the American Society of Civil Engineers, were re-analyzed in 

 terms of deep water parameters. Use of the deep water parameters provides 

 a constant relative depth value as a reference, thus making the data 

 somewhat easier to use. These revised curves are being published in a 

 discussion of this paper in the September 1960 American Society of Civil 

 Engineers Waterways and Harbors Division Journal. 



(c) Study of Sand Bypassing Operations. 



An attempt is being made to gather all available data on sand by- 

 passing operations (past, present, or planned) for correlation and study. 

 The hydrographic survey data obtained in the Port Hueneme area in June 

 1959 are being analyzed. A field observation program has been organized 

 for the vicinity of the new Ventura County Harbor at which bypassing 

 operations are scheduled to start in the future. This operation utilizes 

 an offshore breakwater (parallel to the shore) to form a protected area 

 which serves as a sand trap. Sand deposited in this protected area will 

 be dredged and bypassed to the downdrift side of Port Hueneme. A general 

 study is under way of the applicability of using a radioactive source 

 type instrument with velocity meters to measure quantity of material 

 pumped in bypass operations. 



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