Determination of parameters range in rock engineering by means of Random Set Theory

Uncertainty arising from our relationship with the real world can often lead to imprecise probabilities, whose bounds are captured by Random Set Theory. Reasons leading to this kind of uncertainty in rock engineering are investigated, as well as the limitations of the probabilistic approach. Procedures are given to handle the usual information gained either in the field or from expertʹs opinions, taking into account not only dissonance, but also non-specificity. Examples of applications are presented with special regard to event tree analysis, rock mass classifications, and reliability-based design of tunnels by means of the empirical recommendations of rock mass classifications.