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Owing to the heavy rainfall, a landslide occurred at the Anqian Iron mine, at 18:00(UTC + 8) on November 24, 2019, in China. The landslide was about 3.0 × 104 m3 and caused damage to the road of transporting waste materials. Failure characteristics and the mechanism of this landslide were analyzed in this study. The landslide area was divided into three parts: the rear tension cracking area, the middle sliding deformation area, and the front colluvium area. A contact-free measuring technique using the new ShapeMetrix3D system was applied and 204 joints were analyzed based on equal-angle stereographic projection. Thus, a conceptual model of the mechanism of the landslide was constructed and the formation process of the landslide was divided into three stages: the first shearing and dislocation stage; the second sliding, front bulging, and rear tractive cracking stage; and the third local rock mass collapse and colluvium depositing stage. Numerical modeling was performed to discover the landslide mechanism by progressively reducing the shear strength of rock mass. The results showed that the original slope was stable, whereas heavy rainfall triggered the landslide, and the predicted failure surface matched closely the field investigations. The factor of safety obtained by real three-dimensional analyses was slightly higher than that obtained by plane problem analyses, and the difference was attributed to the three-dimensional effect of the landslide. This paper also presents the results obtained from the parametric analysis in order to understand the impact of shear strength parameters on the overall stability of the slope. [ABSTRACT FROM AUTHOR]

This paper presents a study of the failure mechanism and control measures for a landslide at Dagushan Waste Dump. In addition to a summary of the site geological conditions, the observed landslide shape is described based on site investigations. It is shown that the dominant causes of the slope stability problem are softened silty clay due to rainfalls and the mechanical vibrations of a concrete batching plant at the slope toe. Failure mechanism analyses were performed by base friction test, which showed that the failure mode of Dagushan Waste Dump is a collapse-traction-push type landslide. Dump stability analyses were performed using the limit equilibrium method, which showed that safety factors of the waste dump decrease with the increase of water content of silty clay, and with the increase of average vibration acceleration of mechanical vibrations. The water content of silty clay has a much greater influence on dump stability than the average vibration acceleration. Remedial measures to stabilize the unstable zones include slope reshaping, platform compacting, drainage system ameliorating, and cracks filling. The results indicate that these measures are effective in controlling the landslide. [ABSTRACT FROM AUTHOR]