Consequently, parameters \(n\) and \(B\) implicitly reflect rock characteristics. This suggests a potential link between these parameters and rock classification, warranting comprehensive studies of rocks from various deposits. Such research would involve analyzing the correlation between characteristic points and segments of the stress-strain curve and the mechanical response of rock specimens under uniaxial compression, considering their fracture patterns. The analogy between rock and concrete, a widely accepted rock analog, facilitates this analysis by enabling the use of findings from recent studies [17] that reexamined traditional concepts of concrete's compressive strength. Study [17] emphasizes two principal damage models for concrete under uniaxial compression: longitudinal tensile cracks and inclined shear cracks. As noted above, failure mechanisms correlate with ultimate strength, defined by the peak stress. This parameter varies with the mode and nature of failure. Distinct mechanisms, such as hourglass or shear failure, display different patterns of damage accumulation and propagation within the material. These differences influence the normal and shear stresses needed to reach ultimate strength. The type of failure is influenced by deformation conditions, including strain rate and contact friction. Notably, peak stress decreases when friction between the specimen's contact zone and the testing machine's plates decreases [17] (Figure 3). The boundaries of the above-mentioned intervals (Figure 2) outline the time sequence of destruction stages, recognizing that the tensile strength of rocks is considerably lower than their shear strength [2]. Therefore, tensile cracks emerge within the initial interval,  
Figure 3: Patterns of specimen’s destruction depending on the friction on the surfaces of force con-tact: high friction (**left**); low friction (**right**). Garnet amphibolite. followed by the formation and propagation of shear cracks at an external pressure of approximately \(\sim\)70-90% \(\sigma_{peak}\). Consequently, as external pressure increases during this pre-peak phase, the specimen exhibits a diminishing ability to resist deformation, which reflects a residual bearing capacity ranging from approximately 30 until \(\sim\)10% of \(\sigma_{peak}\)[18,19] (Figure 4). Furthermore, we draw attention to experimental studies [20; 21; 22; 23] which have demonstrated that the failure of brittle rocks is typically associated with a substantial number of tensile cracks and a comparatively smaller number of shear cracks at the macroscopic level. Significant progress has been made through both experimental and theoretical research, including with models addressing uniaxial compression with lateral pressure [1; 2; 3; 8; 17; 19]. However, the balance between the accuracy of the results and the complexity of the algorithms often falls short of meeting the practical needs of engineering applications. This work aims to develop a simplified model for predicting radial cracks within the surface layer of cylindrical rock specimens subjected to uniaxial compression combined with proportional lateral pressure. The model is anticipated to shed light on the primary research question regarding the conditions that lead to the emergence of radial cracks in the surface layer of cylindrical rock specimens and the feasibility of controlling these cracks through adjustments to lateral pressure.