South Australia & NT Chapter

Ground Improvement Techniques

Trevor Osborne

Various geotechnical methods have been employed to alter the properties of soils in order to provide enhanced capacity to support “structures”, as an aid to excavation or for other purposes such as reducing water flows. These methods include vibro compaction, vibro replacement, dynamic compaction, explosive compaction, soil mixing, grouting, pre loading, sand or wick drains and soil reinforcement. The object of improvement may be to increase strength, to reduce settlement or deflection or to change the soil permeability. In many instances the use of ground improvement may result in considerable cost savings compared to more conventional structural solutions such as piling. This presentation gave a general description of various ground improvement techniques along with selected examples from Trevor Osborne’s experience spanning a period in excess of 30 years. Examples presented included:

  • stone columns loaded to over 600 kPa
  • use of vibroflotation as an aid to excavation
  • some recent applications of jet grouting
  • and grouting of mine waste to minimise settlement.

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