Deformation Characteristics and Mechanism of the West Wall of Beiyi Iron Open-pit Mine in Hainan Province

Shilu iron mine is an important iron mine in China, with deposits of 314 million tons and average ore grade of 51.15%, and is the biggest iron-rich deposit in Asia. Beiyi iron open-pit is the biggest open-pit of Shilu iron mine. The height of west wall of Beiyi open-pit is 400m, and the height will be 492m in 2013. Due to the effects of tectonic movements, the rock mass is fractured seriously, and more discontinuities paralleling the slope are unfavorable to slope stability. Since 1998, the deformation of slope is obvious, with horizontal displacement of about 2.9m and vertical displacement of about 1.5m. On the basis of in situ investigation and monitoring data, deformation mechanism of west wall of Beiyi open-pit is analyzed in detail. The results of this research are useful to the slope safety assessment and the following treatment design.