The Uncertainty of Geological Systems in Geotechnical Calculations

Modeling processes of a very different nature as a rule is concerned with the problem of approximation, inaccuracy and incompleteness of data on the simulated system, with its uncertainty. The concept of uncertainty is closely related to the concepts of heterogeneity and variability. In this study the measure of uncertainty is the correlation distance, which is defined as the length, within which the soil mass is assumed to be homogeneous. The study and analysis of uncertainty is reduced to two tasks: the construction of the uncertainty design model with a quantitative description of various aspects and the subsequent consideration of this model in stochastic calculations. To solve these problems a random limiting equilibrium method (RLEM) was used on the example of the dam stability assessment. An analysis of the results showed that under conditions of uncertainty of geotechnical system safety factor (Fs) is not a reliable parameter characterizing the dam slopes stability. With an increase in the heterogeneity of the soils composing the dam body Fs does not change, however, the probability of destruction increases. Also, the effect of heterogeneity on the slope stability is established in this work. With an increase in heterogeneity the Fs doesn’t change, but the reliability of the dam decreases.