Slope Stability Project


Rose Villas

  • Toe of steep slope that failed approximately 5 years ago.
  • Cause of slope failure considered to be removal of a retaining wall and a building.
  • The client intended to develop the site at the base of the slope for a new three storey apartment and car park.
  • Lateral movements in excess of 3m at the toe.
  • Significant tension cracks were noted up to 60m up the slope.
  • Short-term stability prior to the de-stabilising demolition works was marginal (Factor of Safety of 1.60)
  • Long-term stability was also marginal with a Factor of Safety of 1.23.
  • Following the slip of the slope the residual strength properties of the soils and assumed slip surfaces beneath the slope indicate that the Factor of Safety is inadequate for both short-term and long-term conditions.
  • It was considered necessary to implement a remedial technique for the slope due to the marginal factors of safety. This was problematic as the slope failure involved land outside the control of the client. Currently the client is considering several different engineering solutions for the development of the site.