The efficiency of disposal of dredged spoil can be measured quantitatively using the unique properties of radio-active tracers. The technique consists of seeding the spoil with tracer and then tracking the movement of the discharged spoil following disposal. Material carried away in suspension in the water is measured by means of a vertical array of radiation detectors attached to a tracking vessel. The distribution of spoil deposited on the bed is measured by a single radiation detector towed over the bed. A recent short term field experiment in the River Plate, Argentina compared the efficiency of disposal of dredged silt by hopper-dump and side-casting methods. The proportion of dredged spoil effectively removed from the channel by the dredging operation was computed from the tracking data for each spoil disposal method. The resulting data can be used in conjunction with known operational constraints to estimate the effective spoil output from each dredging method with respect to a common dredger operating time. Experiment has shown that under suitable geographical and hydraulic conditions the saving in non-productive time implicit in the side-cast method of disposal more than compensates for the lower disposal efficiency to give a greater effective rate of spoil removal. The results also suggest further experimental studies which could lead to an improvement in the efficiency of side-cast disposal.

  • Supplemental Notes:
    • Paper D-1 from BHRA Engineering Symposium, University of Kent, Canterbury, England.
  • Corporate Authors:

    British Hydromechanics Research Association

    Cranfield MK43 0AJ, Bedfordshire,   England 
  • Authors:
    • Waters, C B
    • Thorn, MFC
  • Publication Date: 1975-9

Subject/Index Terms

Filing Info

  • Accession Number: 00128408
  • Record Type: Publication
  • Source Agency: British Hydrodynamics Research Association
  • Files: TRIS
  • Created Date: Dec 29 1975 12:00AM