Incorporating variability and/or uncertainty of rock mass properties into gsi and rmi systems using monte carlo method

Abstract

This paper introduces a probability-based methodology that can be used to evaluate alternative approaches on account of the uncertainties associated with predicting the rock mass properties. The use of this methodology is illustrated through its application for two rock mass case studies. In this regard, the probabilistic spreadsheet models are developed for the strengThestimation of Kizilkaya ignimbrite and New Zealand greywacke. The frequency histograms and/or the density functions that best describe the data distribution are used as inputs in GSI and RMi systems. This approach allows the variability and/or uncertainty of the available data to be adequately taken into account during simulations. The developed spreadsheet models are also used to quantify the influence of various material and discontinuity characteristics on the resultant strength properties of the studied rock masses. Sensitivity analysis explicitly shows that joint spacing and UCS of intact rock are the most effective parameters on the estimated rock mass strengths.