The stability analysis of homogeneous rock slope following the Hoek–Brown failure criterion under the hypothesis of different flow rules is performed based on limit equilibrium and finite element methods. The applied failure criterion is the generalized Hoek–Brown that can be introduced as a shear/normal function in analysis applying different flow rules. The results are compared with those obtained by the application of equivalent shear strength parameters of the Mohr–Coulomb criterion, considering that this is still the most widely used criterion in rock slope stability analysis and is still the base for the shear strength reduction method applied in finite element modelling. Different proposals for estimating the equivalent strength parameters based on confining stress level are evaluated. The limitation of stress-dependent linear Mohr–Coulomb parameters is emphasized by analysing the vertical cut problem, for which, depending on the chosen stress level, different critical heights are obtained for the same material. Sensitivity analysis of geotechnical parameters used as input for failure criterion is performed to determine their influence on slope stability. Probabilistic analysis is conducted to determine the probability of failure when different flow rules are applied. If slope stability analysis is performed with an assumption of associative flow rule, the probability of failure is within the acceptable limits for the considered case study, while employing non-associative flow rule, the probability of failure is rather high. The chart is presented that could be readily used to estimate the combination of σ_ci, GSI, and m_i values that produce failure for the analysed case study.

Considering the increasing requirements for the recovery of different natural and industrial waste materials, the application of volcanic ash as an alternative sustainable binder to traditionally employed lime and cement is proposed for soil stabilization for geotechnical engineering purposes, thus providing a reduction in carbon emissions. Soil stabilization was performed on natural clays with very high swelling potential, i.e. those classified as inadequate for reuse as a building material for geotechnical purposes. A mineralogical and chemical characterization of raw materials was carried out prior to the performance of different geotechnical laboratory tests, i.e., testing Atterberg limits, compaction, swelling potential, compressibility and resistance parameters over naturally remolded clay and soil mixtures with different binders. The swelling potential was reduced with an increase in the amount of applied binder, necessitating the addition of 10, 20, and 30% of volcanic ash compared to 3% lime, 3% cement and 5% lime, respectively, for a similar reduction in swelling potential. An investigation of the resistance parameters for soil mixture specimens that provided a suitable reduction in swelling potential for their reuse was performed, and a comparison to the parameters of naturally remolded clay was made.

The comparative slope stability analysis of the highly fractured rock slope by three different methods is presented. The usually applied slope stability methods of the rock mass obeying the Hoek and Brown failure criterion comprises the limit equilibrium and/or the finite element method, quantifying the slope stability by the factor of safety. The better knowledge of the entire process of rock slope failure, i.e., the initiation, development of micro-cracks and final position of the failure surface, capturing large deformations, damage and breakage through the rock mass material could be achieved by the implementation of discrete element modeling. In this paper, the application of these three methods for the analysis of failed rock slope case study is shown. The analysis showed that all three methods produce similar results regarding the factor of safety value and position of the failure surface, being in line with the position of the failure surface observed in situ. The discrete element method gives the best prediction, providing a more in-depth knowledge of the failure, estimating the factor of safety by a new approach.

The influence of the non-associative flow law on the bearing capacity of shallow foundations on rock masses is, in general, a subject that is not discussed in the field of rock mechanics. The calculation methods of bearing capacity usually do not define which flow law is adopted and, in some methods, the associative flow rule is assumed without knowing how that hypothesis influences the bearing capacity of the rock mass. In this paper, the study of the influence of the dilatancy angle on the bearing capacity of shallow foundations on rock masses is presented. The variation of the bearing capacity with the associative flow law and the non-associative flow law with zero dilatancy angle is studied using the finite difference method and by considering the influence of the self-weight of rock material. The calculations confirm the great influence of the flow law on the bearing capacity and a correction coefficient is proposed, which makes it possible to estimate the variation of the bearing capacity of the rock mass in terms of the function of the flow law for the hypothesis of weightless rock masses.