Investigation of high rock slope failure mechanisms: a case study of a uranium mine in Namibia

The instability and failure of high rock slopes have a significant impact on the safe mining operations. Therefore, revealing the instability mechanism of high rock slopes is of great research significance. This paper aims to reveal the instability mechanism of high rock slopes through physical model tests and numerical simulations. Taking the slope failure on the west side of Pit 1 of Husab Uranium Mine in Namibia in 2021 as the research background, a physical model of the high rock slope of Husab Uranium Mine was established by combining with on - site geological data. The experimental system was monitored by a GoPro camera, a CCD camera, and strain sensors. The damage evolution process of the high rock slope model was analyzed, and numerical simulation verification was carried out using Flac 3D software. Thus, the instability mechanism of the slope failure in this open - pit mine was revealed from multiple perspectives. The results show that the instability mechanism of the high rock slope was determined through the evolution of the displacement field and strain field during the model excavation process, as well as the deformation characteristics of the images at the time of instability and failure. The slope deformation process can be divided into four stages: the initial inter - layer dislocation stage, the crack generation stage, the crack propagation stage, and the crack penetration and failure stage. The results of the model experiment and numerical simulation confirm the consistency between the failure mode of the model slope and the actual slope failure on - site, providing guidance for the prevention and control projects of similar types of mine failures.