Abstract:  The uneven development of the internal dump and the adjacent stope slope in the open-pit
coal mine area is easy to induce large-scale landslides，which has become a major hidden danger threaten⁃
ing the safe mining of open-pit mines. Focusing on the slope of stope and inner dump in Zhundong Open-pit
Coal Mine，based on the field investigation and analysis of the factors affecting the slope stability，the fail⁃
ure mode and stability of the current slope under natural and saturated conditions are analyzed by means of
Phase2 finite element simulation software. The results show that groundwater and weak layer are the main
factors affecting slope stability. Due to the steepness of the deep slope，the western slope is prone to shear
failure along the coal seam floor，the southern and eastern slopes are prone to local step shear sliding fail⁃
ure，and the inner dump slope is prone to single-step circular sliding failure. At present，the slope of the
stope and the inner dump is in a stable state. In view of the above research，the prevention and control mea⁃
sures of optimizing slope shape，establishing waterproof and drainage system and monitoring and early warn⁃
ing mechanism are put forward. The research results have reference significance for similar open-pit slope
production design and landslide mechanism research.

Key words: open-pit coal mine, slope in inner dump, numerical simulation, slope stability