Slope Stability Analysis of Open-Pit Mines Using Statistical Methods

A non-traditional method of slope stability calculation is presented, which often occurs during geotechnical design. The possible occurrence of slope failure is not illustrated by a safety factor but by the probability of failure. The result is the percentage of failure or, the safety of the stability that can be expected for a given slope. Unlike the deterministic calculation, not a constant value is given for each input parameter but statistical variables according to the distribution belonging to the sample data set, such as mean, standard deviation, relative minimum, and relative maximum. An approach is taken to how slope resistance calculations can be performed on a probabilistic basis through a case study. The subject of this case study is Hungary's largest open-pit lignite mine in Visonta, eastern Hungary. On the optimised sections using the deterministic method, the slope resistance test was performed on a probabilistic basis. The analysis of statistical parameters is also presented as the most important step of the investigation. To determine the input parameters for the probabilistic analysis, the first step is collecting the shear strength values (in this case, friction angle and cohesion) and then deriving a statistical distribution, carrying out the goodness of fit test finally determining the parameters.