A LOGNORMAL SIZE DISTRIBUTION MODEL FOR ESTIMATING STABILITY OF BEACH FILL MATERIAL

This report discusses the problem of estimating the "extra amount" of beach fill to be used when the available borrow material characteristics are finer than the native sand composing the beach area. It is shown that an estimate of the extra amount of fill needed can be found if the native or design sand is better sorted than the available fill, regardless of whether the mean grain size of the borrow material is finer or coarser than the native sand. However, if the available fill is better sorted than the native, or design sand (again regardless of the relative mean grain sizes), there is no direct mathematical solution to the problem. In these latter cases, until further guiding criteria can be developed, past experience and other empirical data are required in reaching a practical decision regarding the amount of the fill that will be stable when emplaced on a given beach. The mathematical theory underlying the method of analysis is based on a simple model that assumes essential lognormaicy of the particle size distributions. When this condition is satisfied, several generalizations can be made, which are summarized in a table and illustrated by actual or hypothetical examples. In essence, the theory defines a "critical ratio" of the amount of borrow material needed to produce a size distribution in the stabilized fill that is the same as that of the native sand. When the ratio has a maximum the problem can be solved, and this depends upon the degree of sorting being better in the native sand than in the borrow material. /Author/

  • Corporate Authors:

    Army Coastal Engineering Research Center

    5201 Little Falls Road, NW
    Washington, DC  United States  20016
  • Authors:
    • Krambein, W C
    • James, W R
  • Publication Date: 1965-11

Media Info

  • Features: Figures; Tables;
  • Pagination: 17 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00264285
  • Record Type: Publication
  • Report/Paper Numbers: Tech Memo No. 16
  • Files: TRIS
  • Created Date: Jan 16 1975 12:00AM