SIMULATION OF DEFORMATION OF SOFT COAL ROADWAY SURROUNDING ROCK UNDER NON-UNIFORM IN-SITU STRESS

Soft coal seams usually have very poor cementing properties, and surrounding rock instability will occur during coal mining, which will endanger the safety of coal mining operations and the surface ecology. Based on this, in this paper, a numerical simulation model of soft coal roadway surrounding rock deformation under non-uniform in-situ stress is constructed to analyze the influence of in-situ stress difference level on soft coal roadway surrounding rock deformation. Comparing the research results with published literature, it is found that the difference in the amount of surrounding rock deformation between the two studies under the same simulation conditions is only 2.01 cm. Such similar simulation results show that the mathematical model constructed in the article can be used to simulate and analyze the deformation and instability of surrounding rocks. In addition, the study also found that as the in-situ stress difference level increases, the stability of the roadway and surrounding rock will gradually deteriorate. When the in-situ stress difference coefficient is increased from 1.25 to 1.75, the area of the yield instability area of the surrounding rock will increase from 5.26 m(2) to 17.95 m(2). This is mainly because the greater the level of heterogeneous in-situ stress difference, the more significant the stress concentration effect in the surrounding rock will be caused by roadway excavation and coal mining operations during coal mining. The study believes that the stability of the roadway and surrounding rock can be achieved through accurate understanding of the in-situ stress status of the coal seam and its appropriate adjustment.