Volume 13 (Continued) 



Research Facilities and Special Equipment of the Beach Erosion Board 



Major research and development facilities at the Beach Erosion 

 Board laboratory are identified and described. Compiled by George 

 W. Simmons of the Beach Erosion Board staff. 



Notes on the Formation of Beach Ridges 



Mechanics of beach ridge formation are discussed on the basis 

 of observations involving wave action on sand beach in laboratory 

 wave tanks. The shape of a beach ridge is explained by considering 

 the relationship between relative wave runup (R/H) and beach slope, 

 as for any constant deepwater wave steepness and wave height, the 

 relationship between runup and beach slope assumes a characteristic 

 curve with runup increasing as the slope steepens, to a maximum 

 value, then decreasing somewhat. J^ritten by Rudolph P. Savage. 



Volume 14 - July 1960 



Sealing of Mission Bay Jetties, San Diego, California 



Grouting of the north jetty to make it impermeable to the 

 passage of sand through the jetty into the navigation channel is 

 described and illustrated with a number of photographs. Materials' 

 selected for the grout mixture, details of the equipment and place- 

 ment operation, and costs are also discussed. Written by Robert E. 

 Loudon, U. S. Army Engineer District, Los Angeles. 



Preliminary Considerations of the Use of Radioisotopes for 

 Laboratory Tracer Techniques 



Preliminary results of an investigation of the feasibility of 

 using radioactive tracers in laboratory studies of sediment move- 

 ment are presented. Feasible objectives obtainable through this 

 use, choice of carrier and radioactive label, are discussed, and 

 potential dose rate calculated. Written by Norman E. Taney, Beach 

 Erosion Board staff. 



Experimental Determination of Wave Pressure Attenuation 



Utilizing controlled wave conditions in a laboratory wave tank, 

 simultaneous measurement of surface fluctuation and bottom pressure 

 was made and compared with pressure fluctuation computed from wave 

 theory. Correction factors obtained in this manner averaged 1.12, 

 in general agreement with the va I ue of I.I previously indicated by 

 work at the University of Ca I ifornia. Written by George W. Simmons. 



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