This paper is the result of geological survey engineering.

Objective Several failures of gneiss-dominated open-pit slopes in China's cold regions at high altitudes and latitudes have recently led to substantial casualties and economic damage. This underscores the critical need to study their deformation patterns and driving mechanisms.

Methods This paper focuses on the September 14, 2023, landslide at the Jinbao Mine in Xinjiang. Through field investigations and deformation monitoring, the characteristics and patterns of its deformation and failure were analyzed. Based on the mechanical parameters of gneiss foliation and rock mass under different conditions, discrete element numerical simulations were conducted to study the mechanism of slope deformation and failure.

Results The landslide was a bedding deformation failure caused by upper bedding slip and toe compression-shear buckling. Under natural conditions, the slope remains stable. However, under the influence of freeze-thaw cycles, rainfall, and blasting loads, the shear strength of the gneiss foliation and the shear and compressive strength of the rock mass continuously decrease. This leads to an increase in the downward sliding force along the foliation in the upper part of the slope and a greater load on the lower toe. As a result, the rock mass at the toe bends, gradually fractures, and develops shear failure surfaces. These surfaces connect with the failure surfaces along the foliation in the upper part, forming a continuous failure surface, ultimately causing overall instability of the slope.

Conclusions The failure process exhibits clear retrogressive dynamics, where the lower toe fails and shears out first, causing the upper slope to lose support and slip downward. The research results provide certain guidance for stability evaluation and prevention design of gneiss-dominated open-pit slopes in cold regions at high altitudes and latitudes.