Verification of the structural and tectonic framework of the Nezhdaninskoye open-pit mine rock massif

The article analyses the studies of factors affecting bench stability in the Nezhdaninskoye open-pit mine. It is determined that the fundamental factors are the vector location and characteristics of faults and cracks in the rock massif. The following three main systems of extended block-forming fractures were defined: (1) subvertical fractures with strike azimuth A = 290°; (2) fractures with strike azimuth A = 50° and dip angle into the massif P = 70°; (3) fractures with strike azimuth A = 50° and dip angle into the pit P = 40°. Basically, the extended surfaces of the rock massif discontinuities lie at an angle of 40-50° towards the mined-out space of the open pit. Individual extended fractures have the angle of 60-65°. The most probable fracture systems involved in bench collapse in case of unfavourable combination of the slope direction and the fracture system's dip are traced in the south-eastern walls of the open pits. There are no unfavourable surfaces in the northern and north-western walls. At the same time, faults running parallel to the benches create potential collapse zones, which requires additional measures to ensure their stability. The structural and tectonic framework of the rock massif has a significant impact on the formation and stability of the open-pit benches. Taking these factors into account when planning and developing open-pit mines will help ensure occupational safety and high efficiency of the mining process.