Study on the interlayer discontinuous stress transmission law of coal mine roadway roof

In order to explore the stress transmission mechanism of layered roof in coal mine roadway, three models with different types and quantities of roof rock layers were made by numerical simulation software, and their influence on rock stress and displacement was analyzed. The first condition is all soft rock, the second condition is a combination of soft and hard layers, and the third condition is a combination of soft, hard and soft layers. The results show that the stability of the rock layer containing hard rock is significantly better than that of the combination of completely soft rock, and the supporting effect of hard rock reduces the stress and displacement changes. Further comparison between Case 2 and Case 3 shows that the simple rock formation assemblage has higher stability, while the complex assemblage increases the uncertainty of stress fluctuations.