Sub Surface provide Slope Stability Analysis Reports for slopes, with or without retaining structures (proposed or failed), assessing the short term and long term conditions to provide a safe and stable design of sloping sites nationwide.

Slope Stability Analysis is an integral part of any development on a sloping site, to determine the stability of the existing slope and to ensure failure does not occur when a surcharge load is applied. Catastrophic failure can occur on sloping sites if Slope Stability Analysis is not considered.

With over 45 years’ experience we have a carried out Slope Stability Analyses on a wide range of projects from small scale single section slope stability projects to large scale multi section catastrophic failure projects.

What to Expect from a Slope Stability Analysis

To assess the stability of the slope, one of our experienced Engineers we will design a site specific Ground Investigation to determine the:

  • Profile of the slope
  • Geological sequence within the slope
  • Groundwater levels within the slope
  • Effective Stress Parameters of the strata from laboratory testing such as:
    • Consolidated Drained Peak Shear Box Tests
    • Consolidated Drained Residual Shear Box Tests
    • Consolidated Undrained Triaxial Tests with pore water pressure measurement
    • Consolidated Drained Triaxial Tests with pore water pressure measurement

The stability of the slope is generally then assessed for the existing profile in the long term using long term (effective stress) parameters, followed by an assessment of the proposed profile using short term (total stress) and long term (effective stress) parameters using Bishop’s method for circular failure planes and Janbu’s method for planar (non-circular) failure planes.

If the Slope Stability Analysis shows the existing or proposed profile to be unstable, remedial measures can be advised and designed, such as: Retaining Walls, stabilisation, etc.

Slope Failures

On sites where a slope has already failed or shows signs of failure, a similar Ground Investigation as above will be carried out, along with determining the reason for the failure and the possible remedial measures and designs.

Whom to Contact

If you would like a quote for a Slope Stability Analysis or have any questions, please do not hesitate to contact your Regional Sub Surface Office.