the revised edition should be available prior to 1 January 1960. 



(1) Re -examination of Beach Protection Projects 



A continuing program is being carried out on the re -examination 

 of artificially nourished beaches to determine the effectiveness of 

 the fill material within the beach zones, and to better establish the 

 factors upon which the desired characteristics of fill material are 

 based. A study of the behavior of the beach fill and borrow area at 

 Harrison County, Mississippi has been made and published as Technical 

 Memorandum No. 107; a similar study of the beach fill placed at 

 Virginia Beach, Virginia was published as Technical Memorandum No. 113. 

 As a part of the study of the durability of materials in coastal 

 structures, a continuing examination of the asphalt groins at Ocean 

 City, Maryland has been made. Re-examination of other projects utiliz- 

 ing asphalt is presently under way. 



(m) Development of In-place Sediment Density Probe 



This probe, which enables a rapid measurement of in-place bulk 

 density of bottom sediment and shoals as a guide to improved dredging 

 techniques, has been calibrated by laboratory tests and has been 

 field tested in estuary sediments and shoals in Savannah River, Georgia 

 and Chandeleur Sound, Louisiana, in reservoir sediments in Hulah and 

 Port Supply (Oklahoma) reservoirs, and in bay sediments and shoals in 

 San Francisco Bay. Calibration and testing was generally satisfactory. 

 Preparation was begun on a report on the development of, calibration of, 

 and field experiences with this gage. The gage has the advantage of 

 giving an indication of densities at successive depths without with- 

 drawing the probe. It appears to have proven itself to be a practicable 

 tool for studying sediment deposits. The probe casing is being stream- 

 lined to enable easier insertion into and withdrawal from the shoal 

 materials. 



(n) Hurricane Studies 



The staff of the Board has continued to support the present 

 hurricane study program of the Corps of Engineers. Considerable work 

 has been done by the staff in developing and improving simplified 

 methods for estimating storm surge elevations and wave heights under 

 a variety of shore line conditions. Wave forces, wave run-up, and 

 wave overtopping phenomena connected with seawall, dike, and barrier 

 design under hurricane conditions have also been studied. A generaliz- 

 ed study of the effect of offshore slope on the amount of wave and 

 set-up observed with high hurricane waves has been initiated. This 

 study will also test the effect on the wave set-up of submerged off- 

 shore barriers, bars, and breakwaters. 



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