Some Ideas to Introduce Risk as a Design Criteria in Rock Slope Engineering

Well known fact is that the process of investigations, design, construction and maintenance of rock slopes is extremely challenging task. The whole life cycle of such structures is affected by many uncertainties related to geological media, non-predictable aspects related to force majeure, possible life losses, selection of apropriate design procedure etc. When talking about design process, in the present geotechnical practice, risk is mainly evaluated indirectly through reliability-based design approaches. There, some criteria are defined in order to estimate the upper limit of the probability of failure of respective engineering structures. On the other side, in this article, the concept is extended, and risk as a design criteria for rock slopes is developed in more details, based on authors’ experiences from some large infrastructural projects. A range of values for Reliability Index (β) and Probability of failure (PF) are proposed in relation to Geotechnical Categories (GC), Consequence Class (CC) and Geotechnical Complexity Class (GCC) as they are suggested in the second generation of Eurocode 7. The proposed methodology is illustrated here with regard to rock slope with impressive dimensions, and it can be a subject for further developements