The article examines approaches to identifying critical displacements and deformations at mining assets using the GNSS observation time series. It is shown that assessing the stability of mining-engineering facilities should not be limited to analyzing absolute displacements of individual stations only, since displacements of the same magnitude may correspond to different stages of the deformation process. Existing approaches to interpretation of the displacement rates, allowable deformations, and hazard levels are reviewed based on an analysis of Russian and international publications, as well as regulatory and methodological documents. Particular attention is given to transition from assessing the kinematics of individual points to analyzing the spatial deformation field. The principal strain axes, dilatation, and maximum shear strain are proposed as informative parameters, which combined analysis makes it possible to identify zones of extension, compression, loosening, compaction, and shear strain concentration. It is shown that universal threshold criteria cannot be directly transferred to all the mining assets and should be refined with regard to the specific engineering-geological conditions, mining regime, characteristics of the monitoring network, and measurement accuracy. It is also noted that reliability of the time-series interpretation largely depends on the quality of data processing, which highlights the relevance of developing domestic high-precision GNSS data processing tools for geomechanical and geodynamic monitoring tasks.
The paper examines contemporary approaches to unmanned excavation using open-pit excavators, with a focus on reducing the human factor through data-driven and digital-model-based control. The objective is to develop and justify a methodological approach to algorithmic control of the digging and loading cycle. The method involves formalizing bucket path control as a multi-criteria optimization problem subject to constraints on the drive loads, face geometry, and safety requirements, combined with the system simulation based on the sensor data and a digital face model. It is shown that a closed-loop control system with feedback on loads and position of the working equipment stabilizes the cycle parameters, reduces the operating variability by 15–25%, and limits the peak loads by 10–18%. Methods are additionally considered for adapting the algorithms to changing face conditions, including the rock fragmentation analysis and telemetry data. It is established that introduction of a virtual loading zone and integration with the in-pit fleet management system improve safety and quality of loading. The results demonstrate that transition to the algorithmic control based on digital models creates prerequisites for conditionmonitored maintenance and further digital transformation of mining operations.
As the mining operations expand, the issue of the change patterns in the physical and mechanical properties of rocks and parameters of their fracturing with burial depth is becoming increasingly relevant. Information available in the published literature does not provide a clear understanding of how these characteristics vary, thereby explaining the need for field and laboratory investigations during the deposit development. This paper presents the results of a comprehensive analysis of structural fracturing and physical and mechanical properties of the core material taken from a subvertical borehole at one of the deposits within the Khibiny massif. In the interval from 340.0 to 841.0 m below the ground surface, the rock mass quality index, linear fracture frequency, density of four rock types and their uniaxial compressive and tensile strength were determined; fault structures and core discing zones were also identified. It is shown how the physical-mechanical properties of the investigated rocks and their fracturing vary with increasing burial depth.
The article discusses a procedure for adapting multi-point statistics to interval-based core sampling data obtained from a copper-porphyry system. The procedure uses irregular borehole sampling and generates local category-based patterns within an anisotropic ellipsoidal neighborhood of a point. The calculation includes the geological domain, lithological rock type, composite type, and aggregated class of the ore potential. Single-layer and multi-layer patterns, distance-weighted and balanced variants of multi-point statistics, indicative kriging, and hybrid schemes were compared for verification. The quality was assessed using a post-hoc validation against the borehole data, employing the proportion of the correct answers, the balanced proportion of the correct answers and the macro-averaged F1 score. For the geological domains, the best result was achieved by a hybrid variant combining multi-point statistics and indicative kriging: the macro-F1 score was 0.401, and the proportion of the correct answers was 0.495. For the lithological types, the best macro-F1 score was obtained by jointly considering the domain, lithological, and composite contexts. For the composite type and the aggregated ore potential class, the best macro-F1 scores were achieved using a distance-weighted approach with class balancing. The results show that the multilayer and distance-weighted templates improve the accuracy of category-based modeling and can be used to refine a geological model.
This study explores the potential for additional geomechanical optimization of the slope design for deep openpit mines during the final operational stage. Feasibility of applying a reduced safety factor of 1.2 for slope sections with the Koashva deposit as a case study. The research provides a detailed analysis of the risks associated with rock mass fracturing, presence of carbonate rock, oxidation processes, and groundwater inflow. An assessment is conducted regarding the inward shift of the top edge of the slope and the consequent reduction in the overburden volume through implementation of a dedicated final development phase. Slope stability calculations were performed using the limit equilibrium method with circular slip surfaces for critical profiles of the hanging wall, where the initial safety factor equals 1.31. Results indicate that shifting the top edge into the ore body by 28.4 to 31.5 meters aligns the slope coordinates at the minus 188 meter level with the design configuration while significantly increasing recoverable reserves at the lower levels. For the adjusted contour during the final development stage, the calculated safety factor ranges from 1.24 to 1.26, fully complying with the regulatory requirements. An integrated approach that combines refined geomechanical modeling, optimized blasting operations, and a hierarchical monitoring system, slope optimization in the analyzed sector is estimated at 4.5 billion Rubles, which is equivalent to eliminating 22.9 million cubic meters of conditional overburden.
