Abstract
Introduction. The relevance of this study is determined by the need to improve the reliability of quarry slope stability assessment under conditions of complex geological structure, intense fracturing of the adjacent rock mass, and increasing geotechnical risks associated with the deepening of open-pit mining operations. The use of digital quarry models generated from UAV-based aerial photography makes it possible to more accurately account for the actual geometry of benches, the structural features of the rock mass, and the spatial location of potentially hazardous zones. The integrated application of photogrammetric data, kinematic analysis, and numerical modeling provides a basis for substantiating safe slope parameters and improving the reliability of design decisions. The purpose of the research to perform a comprehensive assessment of quarry slope stability based on digital models, structural interpretation of fracturing in the adjacent rock mass, kinematic analysis of potential failure mechanisms, and numerical modeling of the stress–strain state of slopes. Research methods and materials. The quarry of the Chiganak barite deposit was selected as the study object. Digital models of the quarry and the adjacent rock mass, generated from UAV-based aerial photography using the VolJet X8Geo fixed-wing UAV and the DJI Mavic 2 Pro multirotor UAV, were used as the initial data source. Photogrammetric data processing was carried out in Agisoft Metashape, while spatial referencing was ensured by GNSS measurements in PPP and PPK modes. To analyze the structural features of the rock mass, fracturing was interpreted from the digital 3D model; as a result, the occurrence elements of fractures were determined, including center elevation, dip angle, dip direction, and strike. Kinematic analysis was performed using Rocscience DIPS. Numerical slope stability modeling was carried out in Rocscience Phase2 using the finite element method and the strength reduction algorithm, while the design of safe slope parameters was performed in Rocscience Slide 2. Research results. As a result of analyzing the digital model of the adjacent rock mass, 248 fracture-orientation measurements were obtained, and three dominant fracture systems were identified. The kinematic analysis made it possible to determine the main potential failure mechanisms: planar sliding, wedge sliding, and toppling. It was established that, with an increase in slope angle from 40° to 65°, the degree of potential failure risk increases, especially on the southwestern wall, where wedge-type displacement is the most probable mechanism. On the northeastern wall, conditions favorable for block toppling are more pronounced. Numerical modeling along profile sections III–X showed that the factor of safety values vary from 0.99 to 1.62 depending on slope geometry, lithological composition, and structural features of the rock mass. The lowest factor of safety was recorded on the southwestern wall along profile section VIII, confirming the presence of a locally unstable zone. Discussion of research results. The obtained results show that digital models of the quarry and the adjacent rock mass provide an effective basis for comprehensive geomechanical assessment. Their use made it possible not only to refine the actual geometry of benches and quarry walls, but also to carry out structural interpretation of fracturing, which is required for kinematic analysis. Comparison of the DIPS and Phase2 results confirmed the consistency of the identified potentially hazardous zones: areas with an increased probability of wedge sliding are characterized by reduced factor of safety values. When designing overall slope angles in Slide 2, it was established that the regulatory stability level, FoS ≥ 1.3, is achieved at different angles depending on the lithological type of rocks: 23° for argillaceous shales, 32° for jasper quartzites, and 39° for jaspers. In addition, the need to account for the technogenic load from the waste dump located near the northeastern wall was established, with a minimum distance of at least 50 m to be maintained from the upper edge of the wall to the toe of the dump. Conclusion. The comprehensive approach to quarry slope stability assessment, based on the integration of digital models, structural analysis of fracturing, kinematic assessment, and numerical modeling, makes it possible to reliably identify areas with reduced stability and substantiate safe slope parameters. The use of Rocscience DIPS, Phase2, and Slide 2 provides a consistent transition from the analysis of the actual rock mass structure to the calculation-based substantiation of design decisions. The proposed approach is an effective tool for improving mining safety and can be applied in the design, monitoring, and adjustment of quarry slope parameters under complex engineering-geological conditions. Conclusions. The application of digital models of the quarry and the adjacent rock mass provides a reliable spatial basis for slope stability assessment. Kinematic analysis identified the main potential failure mechanisms and confirmed the influence of slope angle on the degree of geomechanical risk. Numerical modeling made it possible to determine the range of factor of safety values and identify the most vulnerable areas of the rock mass. The calculation of design slope parameters demonstrated the need for a differentiated approach to selecting overall slope angles depending on the lithological composition and structural features of the rock mass. The developed comprehensive approach has practical significance for ensuring quarry slope stability and improving the reliability of geotechnical design decisions.