John S. Hale


This paper demonstrates the results of the comparison between the calculated alignment of the beach's plan view end the actual alignment that resulted from the natural wave action. A new groin system was designed to replace an existing one, Th? new groin system and spacing ujas designed to hold the beach fill at the required width during average wave conditions as well as changing storm wave conditions. The system was designed for Las Tunas Beach, a beach near Los Angeles, California, In other words, the energies are tabulated for all storm conditions, and the beach alignment is recalculated for changing storm conditions. As the beach plan view alignment rotates back and forth with changing storm directions, it must always meet the minimum beach width requirements. This may entail changing the groin lengths, heights and spacing several times before the design complied with all requirements. Surveys from 1929 to 1970 showed that the beach did not have long periods., periods of several years, of constant ernsion or constant accretion. If there are no major man made changes, it is safe to assume that nature will provide an ad^ruate sand supply. L=s + , but not. least, the calculated beach alignments check with the empirical information gathered from years of survey;ng.


sand fill; groin; groin system

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