Slope Stability Numerical Analysis and Landslide Prevention of Coal Mine Waste Dump under the Impact of Rainfall-A Case Study of Janina Mine, Poland

In Poland, the mining waste from underground coal mines is commonly deposited in surface dump sites, forming slopes or piles of materials dozens of meters high. Because of the loose structure of a mine waste dump slope, landslides may occur after a heavy rainfall. This requires significant labor costs in reforming the mine waste dump sites and disturbs the continuity of the depositing operations. Moreover, if the mine waste dump sites located in the built-up areas, such as in the Janina mine waste dump, landslides apparently can threaten even lives and properties. Therefore, a mine waste dump stability analysis is necessary for ensuring safety. In this paper, slope stability analysis was conducted using numerical modeling under the impact of rainfall for the Janina mine waste dump, located in Libiaz, Poland. The results indicated that slope tends to loose stability in case of high rainfall intensity and short duration. Then, slope reinforcement using soil nailing and steel mesh was proposed to prevent landslide under the impact of high rainfall intensity. Once again, slope stability analysis was carried out with selected reinforcement. Meanwhile, slope monitoring was performed to assess the slope reinforcement implementation at the Janina mine waste dumps against the impact of high rainfall intensity. Based on the modeling and monitoring outcomes, assessments of slope stability and selected landslide prevention measures for the Janina mine waste dump under the impact of rainfall were presented.