Investigating the stability and anchor support parameters of slopes subjected to wetting and drying cycles in relation to the Nanfen open-pit mine, China

Periodic rainfall and evaporation have a major influence on slope instability. In order to explore the changes in seepage characteristics and the stability of slopes under wetting–drying cycles, finite element numerical simulations have been conducted using a case study of the Nanfen open-pit mine in China. The slope stability analysis has been based on the strength reduction method and the effectiveness of anchors was also studied. The results showed that the slope safety factor decreased nonlinearly under the action of the wetting–drying cycles. The pore water pressure of the slope responded quickly to the wetting–drying cycles and had a certain lag, which changed periodically with the process of rainfall and evaporation. When strengthening the slope with anchors, the effects of the anchoring parameters such as anchor length, inclination angle, and installation position on the slope reinforcement effect needs to be investigated. The change in anchor parameters was found to affect the position and depth of the potential sliding surface, thus affecting the stability of the slope. When installing anchors in a slope, the combined effect of the favorable parameters should be considered to ensure a balance between the benefits of the anchor in improving the stability of a slope and the associated economics of the anchoring system.