Use of the probabilistic method of calculating stability when designing rock slopes

Abstract

1. At present rock slopes are usually designed on the basis of the most unfavorable (of those possible) arrangement of potential shear joints in the investigated mass and without consideration of the probability of the presence of joints of such orientation in it. 2. A new method is proposed here for calculating the stability of rock slopes based on the use of a statistical probabilistic method of processing the measurements of orientations of potential shear joints and taking as the criterion of stability of slopes their reliability value. 3. The practical use of the method when designing the rock slopes of foundation pits of the Southern Ukraine power complex showed the advantages and prospects of the probabilistic approach to estimation of the stability of masses. In particular, use of the method made it possible to design some steeper slopes, which as a whole for the complex will permit avoiding additional excavation of tens of thousands (potentially as much as 160,000) of cubic meters of rock. 4. The results of calculating slope stability for various values of the hydrostatic pressure indicate the need for special investigations (e.g., on an electrohydrodynamic analogue) to determine the shape of the line of seepage in masses and the expediency of refining this line during excavation works.