Inclination effect of coal mine strata on the stability of loess land slope under the condition of underground mining

The coal seam mining-induced characteristics of overlying strata fracture and surface subsidence are tested and numerically analyzed using the similar materials. Two mining models were conducted in a laboratory with two different rock orientations and slopes to simulate the stability conditions and driving conditions of the loess land slope of under the guides of the V-shaped law. Given a 30° dip angle of coal seam in the Model 1, the results show that the loess landslide on top of inclined rock layers is in the state of critical instability when working face advances to 100 m. Whereas, given a 30° dip angle of coal seam in the Model 2, the loess landslide on top of anti-inclined rock layers is in the state of critical instability when working face advances to 120 m. Numerical analysis using a discrete element method was performed to compare the analysis results with laboratory findings. Based on the test and numerical analysis results both indicate that the land sliding along loess land slope are most likely be triggered on inclined rock layers than anti-inclined rock layers when an underground mining activity begins to excavate.