2. Study of iSelective Sorting! 



a. The slope will be divided into sections down the center 

 of the flume, each section containing a large sar^sle of particles of a 

 uniform size. The selective sorting will than be studied statistically 

 and an attempt made to discover the functional relationship between the 

 variables considered with respect to sorting, 



VI. Waterways Experiment Station, Vicksburg, Mississippi, Progress 

 Report for Period ending 31 May 1953 . 



Wave Run-up on Shore Structures - Overtopping tests and run-up on 

 a structure similar to the Galveston seawall, using a beach slope of 1 on 

 10 and 1 on 25 and a water depth of 29,5 feet involving seawall crest 

 elevations of +3, + 6, +.9, +12, +l5, +l8,-and +21 were completed. These 

 tests show that the run-up is higher on, and more water overtops, the 

 curved-faced wall than the vertical wall tested previously for the same 

 wave conditions. Overtopping and run-up tests on a smooth-faced pavement 

 with a seaside slope of 1 on l| using crown elevations of +3, +6, +9, +12, 

 +l5,+l8,+21 and +2i;, a water depth of 29.5 feet and a beach slope of 1 on 

 10 were completed. 



Effect of Inlets on Adjacent Beaches - Tests are being made in a 

 basin simulating an ocean and a lagoon, irfiich are separated by a barrier 

 beach of sand that can be breached to reproduce the desired inlet. An 

 automatic tide control is used to reproduce tides in the ocean part of 

 the basin, which is also equipped with a 60-ft-long wave machine, and a 

 circulating system to reproduce littoral currents when desired. The 

 barrier beach is first stabilized by operating through a fixed cycle of 

 tides, waves, etc; the desired inlet is then cut through the beach, and 

 the same cycle of operation is repeated until the beach is again stabilized 

 with the inlet in place. Special attention is paid to the physical and 

 hydraulic characteristics of the inlet and the condition of the adjacent 

 beaches. Under the first several conditions tested the inlet closed 

 completely after a very few tidal cycles. The lagoon tidal apparatus 

 has been adjusted so that the inlet will be kept open, and a further 

 test is being undertaken. 



VII, Beach Erosion Board, Research Division, Project Status Report 



for Quarter Ending 15 June 1953T 



In addition to the research projects under contract to various 

 institutions which are reported on above, the Research Division of the 

 Beach Erosion Board is carrying out certain projects with its own 

 facilities. The main unclassified projects were described in Vol, 6, 

 No, h of the Bulletin (October 1952) and a short description of some 

 of the work accomjplished through the last quarter is given below. 



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