The processes of rock excavation and processing involve intense mechanical stresses on cutting, displacing, and transporting tools, inevitably leading to the phenomenon of dry friction wear. The factors influencing the intensity and mechanisms of wear are complex and interdependent, being conditioned by the physical–mechanical properties of the rocks, the geometric characteristics and materials of the tools, as well as the cutting process parameters (cutting force, feed rate). Previous studies have mainly addressed the global aspect of wear without delving into the microstructural evolution of the contact surfaces during the friction process. In this paper, through controlled tribometric tests, we have investigated in detail the abrasive wear mechanisms of metallic materials in contact with different types of rocks, with an emphasis on the role played by surface roughness and the mineralogical properties of the rocks. Experimentally, we varied the applied forces and the number of friction cycles to simulate different working conditions and evaluate how these parameters influence wear intensity and surface morphology evolution. Microstructural analysis of the samples, combined with roughness measurements, allowed the identification of the predominant degradation mechanisms (abrasion, adhesion, fatigue) and their correlation with the material properties and the friction process parameters. The results have shown a strong correlation between the wear capacity of rocks and their petrographic properties, such as hardness, porosity, and hard mineral content. It was also found that the roughness of the contact surfaces plays an essential role in wear mechanisms, influencing both the initiation and propagation of its effects. Depending on the experimental data, we have developed a classification of rocks based on their abrasive potential and proposed criteria for the optimal adoption of materials and working parameters for the tools of technological equipment depending on the type of rock encountered. The results of this study can contribute to improving the durability of tools, as well as mining equipment, and reducing operating costs.

Geomechanical assessment of rocks requires knowledge of phenomena that occur under the influence of internal and external factors at a macroscopic or microscopic scale, when rocks are submitted to different actions. To elucidate the quantitative and qualitative geomechanical behavior of rocks, knowing their geological and physical–mechanical characteristics becomes an imperative. Mineralogical, petrographical and chemical analyses provided an opportunity to identify 15 types of igneous rocks (gabbro, diabases, granites, diorites, rhyolites, andesites, and basalts), divided into plutonic and volcanic rocks. In turn, these have been grouped into acidic, neutral (intermediate) and basic magmatites. A new ranking method is proposed, based on considering the rock characteristics as indicators of quantitative assessment, and the grading system, by given points, allowing the rocks framing in admissibility classes. The paper is structured into two parts, experimental and interpretation of experimental data, showing the methodology to assess the quality of igneous rocks analyzed, and the results of theoretical and experimental research carried out on the analyzed rock types. The proposed method constitutes an appropriate instrument for assessment and verification of the requirements regarding the quality of rocks used for sustainable construction.

The factors that influence the strength characteristics of rocks can be different in nature, being divided into external and internal factors. The mechanical properties of hard rocks are a result of geological, physical and chemical factors. In order to highlight the physical parameters that influence the strength characteristics of the rocks, in this paper there were analyzed six types of volcanic magmatic rocks such as andesites. In terms of stress behavior, rocks are directly influenced by their physical properties, such as volumetric density, porosity, compactness, moisture and the degree of alteration of mineral components. For this purpose, several sets of tests were performed to determine the physical and mechanical characteristics of the rocks, based on which it was possible to analyze how the physical parameters influence the strength characteristics.

Land subsidence and structural instability at the Slănic Prahova salt mine have evolved significantly over 190 years of underground extraction, particularly following the mine’s expansion in 1970. This study reconstructs the complete geomechanical history from 1835 to 2025 and forecasts deformation trajectories up to 2050 using a calibrated creep-based numerical model. A high-fidelity geological model was developed in Leapfrog Works, with the numerical mesh generated in Rhinoceros and converted to FLAC^3D format via the Griddle plug-in. Salt creep was characterized using a Norton power-law constitutive model, with initial parameters derived from the steady-state phases of laboratory creep tests, and subsequently with calibrated parameters identified at the mine scale as n = 2.03 and A = 3 × 10⁻²⁵ s⁻¹ MPa⁻ⁿ. The simulation results demonstrate a high degree of correlation with field observations. These parameters were subsequently refined at the mine scale by integrating surface leveling data (1994–2025) and underground displacement records (2004–2019). The simulation results demonstrate a high degree of correlation with field observations, highlighting critical deformation zones. Maximum surface subsidence increased from approximately −560 mm in 1970 to −1020 mm by 1992, reflecting the intensified impact of later mining phases. The current maximum cumulative displacement is estimated at −1640 mm (2025) and is projected to reach −2060 mm by 2050. Underground, the largest displacement rates are concentrated in the eastern sector, driven by the synergistic effects of overburden loading and regional horizontal stress.