# Geomechanical Basis for Assessing Open-Pit Slope Stability in High-Altitude Gold Mining
## 4 Conclusions  
1. A rational methodology for determining the strength characteristics of rock masses in situ was developed and tested through the preparation and shearing of rock prisms under field conditions. The methodology included selecting the geometry and configuration of the prism and using a calibrated hydraulic jack as a shearing mechanism. Field tests conducted at the Bozymchak pit revealed the in situ cohesion values for marbled limestones and granodiorites, with the results presented in Table 1.
2. A method was tested for determining the orientation of discontinuities and fault fractures, as well as the size of structural blocks in the near-slope rock masses of the pit, using the HDS8800 ground-based laser scanner (Leica Geosystems AG, Heerbrugg, Switzerland). This method enabled the acquisition of the digital geometric model of the rock mass, processed via the specialized software Maptek I-Site Studio (Maptek Pty Ltd., Adelaide, Australia). The obtained data on fracture patterns allowed for the identification of fracture systems for the northern wall. The orientation of the identified fracture systems was analyzed based on their azimuth and dip angles (Figure 9), where five main sets (I-V) were identified. The yellow shaded areas in the diagram indicate the prevailing dip directions of each fracture set. I: A = 54\({}^{\circ}\), \(\delta\) = 80\({}^{\circ}\); II: A = 115\({}^{\circ}\), \(\delta\) = 69\({}^{\circ}\); III: A = 193\({}^{\circ}\), \(\delta\) = 75\({}^{\circ}\); IV: A = 230\({}^{\circ}\), \(\delta\) = 45\({}^{\circ}\); V: A = 280\({}^{\circ}\), \(\delta\) = 65\({}^{\circ}\); and for the southern wall with appropriate adjustments. 3. The identified fracture systems were classified in relation to the strike direction of the pit slope walls. The failure mechanisms for rock prisms were identified using the slope stability classification in anisotropic media developed by Prof. [PERSON]. Stability assessments were carried out accordingly (Tables 2 and 3). Figure 9: Fracture systems orientation diagram: fracture sets I–V are marked with Roman numerals; the yellow sectors correspond to the dominant dip directions of the detected discontinuity systems. The results of the slope stability analysis within the southern wall's design contour indicated the presence of three downward-dipping fracture systems (stations 1, 2, and 3) in the upper section, which may lead to local rockfall events. In this case, Failure Mechanism VII (as per [PERSON]'s classi@fication) may be realized, with a calculated safety factor of 1.23. Special caution is required during blasting operations in the buffer zone near the design slope line. At station No. 19, a longitudinal, downward-dipping fracture system was identified that may correspond to Failure Mechanism I, with a safety factor of 1.16 under specific conditions. Other areas along the 30 m high southern pit wall were considered stable, with calculated safety factors ranging from 1.96 to 32.0. According to current guidelines, the required safety factor should not be less than 1.5-2.0. Analysis of the northern wall's stability showed that the existing fracture network in the near-slope rock mass did not significantly affect individual bench stability. Even under Failure Mechanism VI (Okatov classification), the calculated safety factors ranged from 3.09 to 5.98. These values meet regulatory stability criteria, with only a minor reduction (0.1) observed under seismic loading. The slope stability assessment of pit walls was performed using the limit equilibrium method and specialized software tools. Cross-sections 1-1, 2-2, 3-3, 4-4, 5-5, 5a-5a, and 7-7 developed by the geological service were used for calculations. The overall stability of the near-slope rock masses along the southern and northern pit walls was confirmed, with safety factors ranging from 1.31 to 2.80. However, certain sections of the northern wall, particularly in the areas of cross-sections 5a and 7, were under higher-stress conditions, with safety factors ranging from 1.310 to 2.785.