煤层群卸压开采上覆被保护煤层回采巷道控制技术

Surrounding rock control in the overlying protected coal seam is a challenging topic of de-stressed mining of multi-seams. Based on current research findings on roadway control, we have designed a physical simulation model of the complex textured- roof with varying thickness to study roadway instability and collapse caused by dynamic pressure. Results show that when thickness of the roof is bigger than that of the bolted depth, the roadway security is in the worst situation and the roof has the greatest possibility to lose its stability. Meantime, we have carried out a numerical simulation to study stress redistribution before and after roadway excavation during underlying protective seam mining. The evolution of roadway displacement and fractures affected by support methods has got studied as well. Then a series of support principles and technologies for mining influenced roadways have been proposed after successful practical applications in Huainan Mines, which are of extended value to deep coal mining support in China.