Knowledge centre

Terminology

Dredging like most industries has specific terminologies which describe abroad range of activities and materials used during operations.
Some of the terminology that is used in dredging includes: Read more
  • Bearing capacity of a foundation is the maximum load that can be applied on a foundation, before failure or uncontrolled deformations occur.
  • Bunds are constructed to create stability of existing subsoils, slope angles and water levels to ensure the integrity of the reclamation area.
  • Bulking occurs when the in-situ density of the material within the borrow area is not equal to the density achieved within the reclamation area.
  • The properties of carbonate sand are different than more commonly used quartz sand and its behaviour must be considered when using it for fill.
  • The density of a soil influences the stability of a land fill and should be carefully measured in relation to the ultimate purpose of the fill.
  • Losses of fill can occur for several reasons and can result in not meeting the quantity of fill required for the dredging operation.
  • Mud waves may occur when the subsoil of a reclamation area is soft, with low shear strengths and can result in inadequate fill mass properties.
  • The permeability of the fill mass influences the drainage capacity of the site and may sometimes require artificial drainage systems.
  • Shear strength is the strength of a material to withstand the type of yield or structural failure where the material or component fails in shear.
  • Slope stability needs to be analysed in certain cases to ensure that the threat of slope failure either in the short or long term will be limited.
  • Soft clays or soft silts in the reclamation area will become soft slurry which can experience significant bulking followed by consolidation.
  • Stiff clays or silts can be dredged by backhoe, trailing suction hopper or cutter suction dredgers which will influence the properties of the material.
  • Stiffness of subsoil and fill will define the deformation or strain which occurs during and after the construction of a reclamation site.
  • Strength of the fill mass will determine its bearing capacity and slope stability and effects the fill mass’s ability to bear the weight of foundations.
  • Subsoils are found immediately under the surface soils and cover a wide variety of properties and show very different behaviours.