BULTFONTEIN ROAD - KIMBERLEY
SLOPE STABILITY EVALUATION
CONTENT
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Input Data for Kimberley Pit Slope Analysis
Results of Slope Stability Analysis
Break-Back Process Analysis
Conclusions
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INPUT DATA FOR KIMBERLEY SLOPE ANALYSIS
KIMBERLEY PIT EAST SLOPE
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BOREHOLES AND SECTIONS
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IDEALIZATION OF SLOPE
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ROCK MASS PROPERTIES
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RESULTS OF SLOPE STABILITY ANALYSIS
DEEP AND SHALLOW SEATED FAILURES
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SUMMARY RESULTS
LIMIT EQUILIBRIUM STABILITY ANALYSIS
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BREAK-BACK PROCESS ANALYSIS
HISTORIC RATE OF BREAK-BACK
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RATE OF BREAK-BACK AND SLOPE ANGLE
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RISK ZONES AS FUNCTION OF SLOPE ANGLE
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INTERPRETATION OF RISK ZONES
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CONCLUSIONS
CONCLUSIONS
The results of the geotechnical analysis indicate that:
• The occurrence of shallow failures in the more disturbed material close to the slope face is more likely due to the natural
degradation of rock mass conditions with time.
• Time is a factor that has an effect on the stability conditions of the slope, but it is also a factor difficult to account for in
engineering models at the present time.
• Current risk to the Bultfontein Road has been defined in a qualitative manner in terms of overall slope angle as low risk (<30º),
moderate risk (30º to 33º), high risk (33º to 36º) and very high risk (>36º). These angles define corresponding zones of risk
around the pit with levels of risk increasing towards the slope crest. The Bultfontein Road is currently located within the low risk
zone.
• Slope break-back and surface deterioration will continue, and periodic shallow failures will be experienced from time to time,
though it is difficult to predict the rate of occurrence of these events. Continuous slope inspections and monitoring are the
available strategies to anticipate the occurrence of failure events.
• The likelihood of a deep seated failure (in the geology underpinning the pit) affecting the Bultfontein Road is very small.
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