DISPERSION OF DREDGED SPOIL WHEN DUMPED AS A SLUG IN DEEP WATER

The motion of dredged spoil when dumped near the surface of deep water as a slug, is formulated using the principle of superposition. The dredged spoil is considered to consist of various fractions of uniform size particles and each fraction exerts an influence on the total behaviour of the dredged spoil in the same proportion as its negative buoyancy. The behaviour of uniform size particles has been formulated using the theory of dimensions and laboratory experiments. The results of the research show that the motion of uniform size particles can be treated in two distinct phases, namely, the initial "entrainment" phase and the final "settling" phase. During the entrainment phase, the size of the "cloud" of solid particles grows due to the incorporation of external fluid while the vertical downward velocity diminishes. During the settling phase when the vertical downward velocity is the same as the fall velocity of individual solid particles constituting the cloud, the increment in the size of the cloud is due to the ambient turbulence only. The method developed in the work permits the evaluation of the vertical height and the horizontal size distribution of the "mound" formed due to the deposition of the dredged spoil at the bottom of deep water. It also indicates how the characteristics of the mound depend on the volume of dump, the size distribution of the dredged spoil, the water depth and the ambient current, thereby providing guidance for the selection of optimum dump size and location for the disposal of the dredged spoil.

  • Supplemental Notes:
    • Paper D-2 from BHRA Fluid Engineering Symposium, University of Kent, Canterbury, England.
  • Corporate Authors:

    British Hydromechanics Research Association

    Cranfield MK43 0AJ, Bedfordshire,   England 
  • Authors:
    • Krishnappan, B G
  • Publication Date: 1975-9

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Filing Info

  • Accession Number: 00128409
  • Record Type: Publication
  • Source Agency: British Hydrodynamics Research Association
  • Files: TRIS
  • Created Date: Dec 29 1975 12:00AM