Pit and Dump Slope Stability and Slope Design Optimisation

Slope stability and slope angle optimisation is critical in the design and operation of open pit mines having significant impacts on safety and on the economics of an open pit project.

Approach

The raw data for slope stability analysis and design comes from a geotechnical investigation programme which is best combined with the exploration drilling programme. For a green field site SRK will undertake a geotechnical drilling programme to characterise the site geotechnical conditions. For an existing operation SRK will undertake mapping of existing pit faces. From the results of this work it will be possible to define the major rock mass, structural and hydrogeological conditions that will influence the design and stability of an open pit slope. SRK will use this information to construct sectional or 3D geotechnical. These will then be input into one of a number of slope stability analysis software within which sensitivity and parametric analyses will be undertaken to establish appropriate pit design configurations that satisfy prescribed factor of safety or failure probability criteria.

SRK use of a variety of geotechnical software for undertaking slope analyses, including:

  • Deterministic limit equilibrium programs for rock mass stability analysis, such as SLIDE and SLOPE-W;
  • DIPS and SWEDGE for kinematic analysis of discontinuity bound wedge stability; and
  • finite difference software, FLAC and FLAC3D, and finite element software,PHASE2, for complex slope stability analysis including fully coupled mechanical/groundwater analysis.

Deliverables

From the results of this work appropriate and cost effective detailed slope designs and/or remedial measures will be developed.

SRK will also recommend appropriate monitoring systems and develop pit slope management procedures to assist the operator to optimise slope design and manage the risks associated with potential pit slope instability in order to minimise production loss.

Experience

SRK geotechnical engineers are international experts in the investigation of the stability of man-made slopes. SRK’s engineers have gained considerable operating experience at some of the world’s largest open pit mines and are recognised world authorities in slope studies for mining operations worldwide.

Services

  • Design and management of geotechnical investigation, drilling and laboratory testing programmes.
  • Core logging, geological and geotechnical mapping using scanline and window mapping systems as well as 3D photogrammetric techniques (Sirovision).
  • Geotechnical databasing, rock mass characterisation and domain modelling.
  • Structural interpretation and analysis.
  • Integration with the pit hydrogeological model.
  • Deterministic and risk based slope stability analysis using 2D and 3D numerical models.
  • Development of slope monitoring and management procedures.
  • Training of site personnel in geotechnical data collection and interpretation.
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