Evaluation of slope stability problems using probabilistic method in adilcevaz limestones along the adilcevaz-ahlat E-99 highway

Rock slope instabilities may lead to casualties as well as property losses along transportation lines in highly weathered or highly deformed rock masses. In practice, stability assessments are frequently executed by analytical or numerical analyses, particularly considering the factor of safety concept. However, the rock masses even the rock material may exhibit inhomogeneity resulting in significant variation in physico-mechanical parameters. Apart from those, discontinuity surfaces, which have a great impact on the stability, are heterogeneous as well. Furthermore, it is quite difficult to assign the most appropriate value for the design parameters to get accurate outcomes. In recent years, the probabilistic approach has been increasingly put into practice in cut slope projects to overcome uncertainties in stability evaluations. In this study, slope stability probabilities of sedimentary rock cut slopes along Adilcevaz – Ahlat state highway are evaluated using the Slope Stability Probability Calculation (SSPC) method. Moreover, the shear strength parameters of the rock mass is calculated through the same approach and compared to the results obtained from Hoek-Brown empirical failure criterion. Consequently, the probabilistic assessment indicates major slope stability problems as a result of discontinuity controlled and orientation independent instabilities. The stability problems along the investigated rock slopes are also verified by field reconnaissance. Therefore, slope redesign and slope reinforcement at the studied locations should be performed in the form of steel mesh, shotcrete and rock bolts.