Abstract: Safety issues are often prevalent in deep open-pit mines. Taking Yanshan Iron Mine as an example,the final boundary slope height exceeds 600 m. The east side,which requires urgent stability evaluation and safety measures,is a typical bedding rock slope. Its stability has been compromised by the seepage of the Xin River,among other factors. To prevent potential landslide disasters,this paper investigates the engineering geological conditions and the structure of the slope rock mass. The strength of the rock mass was estimated using the modified Hoek-Brown criterion. Based on this,the potential instability failure mode and stability of slope are studied by anisotropic finite element method. The study results indicate that the slope′s stability is compromised when the rock dip angle of the calculation model closely aligns with the final slope angle. Consequently,following the completion of the east slope excavation in the N26 exploration line,the benches located in the upper weathering zone and the bottom of the final boundary pit are at risk of sliding out. Based on the aforementioned study,comprehensive measures for slope disaster prevention and control are proposed. These include a combination of water drainage,slope reinforcement, and monitoring,which aim to ensure the safe mining of the east side.

Key words: deep open-pit mine,bedding slope,Hoek-Brown strength criterion,anisotropy,disaster prevention and control