Geotechnical Engineering

Ground improvement

Ground improvement involves treating or modifying the condition of soil or unstable ground by altering the nature of the soil to improve shear strength, stiffness and permeability. For example, poor strength soils can be modified with cement to produce a harder material with improved mechanical properties – lower plasticity, increased bearing ratio and shearing strength, and decreased volume change.

Ground improvement can be used to reduce the excavation costs of unsuitable material and reduce the costs for imported replacement fill materials or the costs of using deep foundations.

RSA Geotechnics expertise in earthworks and ground improvement projects include the determination of optimum soil compaction parameters, specification of fill materials, site monitoring, quality control and performance, design of cut and fill slopes and settlement analysis.

Working in conjunction with specialist ground improvement contractors, RSA Geotechnics can advise on the design, carry out site supervision and verify the ground treatment methodologies. Over the last thirty five years we have been involved with a number of ground improvement projects using a range of stabilisation techniques including:

  • lime and cement stabilisation
  • deep soil mixing
  • vibro-replacement
  • dynamic compaction
  • wick drains and surcharging

Our involvement and expertise can form a significant element in achieving optimum earthwork and foundation solutions, minimum off-site removal of poor soils and significant cost savings. We can supervise and monitor the construction phase to ensure that the engineered fill will perform its structural function in the long term.