Fracture Failure of Consequent Bedding Rock Slopes After Underground Mining in Mountainous Area

Underground coal mining in the southwestern mountainous area of China causes potential large-scale landslides. To prevent the geohazards of consequent bedding rock slopes after underground mining, the deformation and failure configuration were determined by two landslides caused by underground mining. Then, a prediction model for the fracture failure of the consequent bedding rock slopes was established and validated by physical modeling. The prediction model can analyze the stress and bending moment in the consequent bedding rock slope caused by underground mining and predict the location of fracture failure of the slope. The prediction results for the Masangwan landslide showed that the fracture was at 103.5 m as compared to the actual slip length of 114 m, with an error of 10.5 m, and the relative error at 9.21%. The prediction model has good prediction effect. Physical modeling showed that the crack locations from a similar model appeared at specific intervals in the further advancement of underground mining. The rock mass at a distance from the boundary of the separation zone of the slope surface reached the tensile limit when the length of the separation reached the maximum threshold value, producing tensile cracks. The crack locations from a similar model appeared at specific intervals in the further advancement of underground mining. In addition, the error between the crack location and the prediction result was found to be only 0.0352 m, and the relative error was 5.79%. A comparison between the physical and proposed models showed that the predicted fracture failure is consistent with the laboratory results. The prediction and physical model neglect the impact of environmental factors on fracture development, such as the complex geological structure and the physical and chemical transport of water in the rock mass, resulting in a small error in the prediction results. Therefore, the prediction results can effectively reflect the deformation and failure of consequent bedding rock slopes caused by underground mining. The proposed model can serve as a theoretical basis to predict the geological disasters of consequent bedding rock slopes caused by underground mining.