DYNAMIC PROPERTIES OF IMMERSED SAND 

 AT VIRGINIA BEACH, VIRGINIA 



by 



W. Harrison 



U. S. Coast and Geodetic Survey, Norfolk, Virginia ' and 



Virginia Institute of Marine Science, Gloucester Point, Virginia 



and 



R. Morales-Alamo 

 Virginia Institute of Marine Science, Gloucester Point, Virginia 



ABSTRACT 



On March 25, 1963, 219 sand samples were taken from the 

 shoaling-wave , breaking-wave, swash-backwash, and foreshore 

 zones of the beach. The following kinds of measurements were 

 used to describe the properties of the samples: mean settling 

 velocity in nature (as determined with a Woods Hole Rapid Sand 

 Analyzer and a special set of curves for settling velocity as 

 a function of temperature), mean Reynolds number (in nature), 

 and mean drag coefficient (for an infinite fluid under natural 

 conditions). Corey's (1949) shape factor and the Dynamic Shape 

 Factor of Briggs, et al. (1962) were calculated and compared; 

 the Corey shape factor was used in calculating mean settling 

 velocity. Also presented are data for mean and median grain 

 size (in nominal diameter) and sorting for each sample. For 

 the natural sea-water conditions (T = 6.9°C, S = 26.7 o/oo) , 

 average Reynolds numbers for the various zones were 4.8 

 (shoaling-wave), 8.1 ( breaking -wave ) , 6.2 (swash-backwash) and 

 12.0 (swash-berm) . 



The important effect of kinematic viscosity on the dynamic 

 properties of the particles and on beach slopes in the shoal- 

 ing wave zone is considered. Observed trends of mean size and 

 sorting throughout the dynamic zones are compared with those 

 predicted by Miller and Zeigler's (1958) model and the com- 

 parison is found to be rather poor. 



Present address: Land & Sea Interaction Laboratory, 439 York St., 

 Norfolk, Virginia. Study completed while at the Virginia Institute 

 of Marine Science. 



