A report "Solitary Wave Behavior at Concave Barriers" was prepared and 

 given limited distribution by the University of California as Institute 

 of Engineering Research Technical Report, Series 89, Issue 7. This report 

 describes the behavior of a solitary wave as it advances along concave 

 barriers for the case of an initial angle of 12° between the barrier and 

 the direction of incident wave advance. For concave vertical barriers it 

 was found that the wave height at the barrier increased continuously in the 

 direction of wave travel. The condition of the surface of the barrier did 

 not affect this build-up. The wave did not reflect from the barrier, but 

 instead the wave crest bent next to the barrier so that it became virtually 

 perpendicular to it. The highest build-up at the barrier was approximately 

 2.5 times the height of the incident wave. On the other hand, as the soli- 

 tary wave advanced along a sloping rubble mound barrier, this build-up of 

 the wave next to the barrier never occurred. However, there was still no 

 reflection. 



Some preliminary work was done on programming wave diffraction theory 

 for an IBM 704 computer. Some rather small scale model tests were ini- 

 ated to study the effect of bottom slope shoreward of a breakwater on wave 

 characteristics in the protected area (that is, the combined effect of 

 refraction and diffraction). 



V. Dr. W. C. Krumbein (Consultant). Study of Beach Sampling Methods . 



A report "The Analysis of Observational Data from Natural Beaches" has 

 been published as Technical Memorandum No. 130 of the Beach Erosion Board, 

 and summarizes work done on the application of computing machine methods 

 to the study of factors influencing beach characteristics and stability. 

 The report indicates that design of field tests to acquire large and com- 

 plex data must be carefully made, but points out that when such tests are 

 properly designed, there is a high probability that individual sources of 

 variability may be identified and evaluated while in the presence of other 

 naturally occurring but changing variables. The interplay or interlocking 

 of several variables may also be evaluated by the methods derived. Further 

 study, utilizing computer techniques, is being initiated using sand sample 

 data collected near the mouth of the Cape Fear River, North Carolina. 



VI. Beach Erosion Board Laboratory . 



(a) Wave Forces on Structures. 



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

 wave tank on a vertical 12-inch diameter pile. A report was prepared for 

 presentation at the American Society of Civil Engineers Houston meeting 

 in February 1962; it presents the continuous variation of simultaneously 

 occurring wave force, water velocity and acceleration, and wave profile 

 through one or more wave cycles for a limited number of wave conditions. 



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