Authors: Baczynski, NRP
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Examples of statistical models for geological defect attributes are presented. Whilst data collection errors can occur for all attributes, the factors specifically influencing defect length measurements are examined in more detail. Mapped lengths may underestimate actual lengths by 60 to 80%. Hoek–Brown and Step-Path methods are used to estimate shear strength of failure paths through rock slopes. Both methods are compared. For the inputs considered, Step-Path method may yield shear strength results that are up to 40% lower than Hoek–Brown results. Inputs influencing Step-Path results are examined. Implications of Hoek–Brown and Step-Path results for pit slope design Factors of Safety are discussed.

Keywords: factors impacting defect length models, length estimation errors, Step-Path method, errors in rock mass strength, slope stability

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