Principle and Practices on Surrounding Rock Control of Three Soft Seam

In order to solve the roof broken, coal wall spalling, powered support subsided in floor and other difficult surrounding rock control problems occurred in t he mining operation of the coal mining face in three soft seam, based on a physical mechanics test of the surrounding rock and floor specific pressure test in Heigou Mi ne, the theoretical analysis, numerical simulation, site measurement and other study methods were applied to study the surrounding rock control of mining face in three soft seam. Three principles on the surrounding rock control of the coal mining face in the three soft seam were provided. The three principles were the comprehensive C ontrol principles of the roof, coal wall and floor. Based on the three principles, equipment selection design and matched equipment production practices were conducted on the powered support of the coal mining face. The site measured results showed that a working resistance of the powered support in the coal mining face was not hig h. Among the powered supports, working resistance of No.92 powered support was over 3 000 k N in maximum and was only 0.29% of the designed resistance. A spall ing depth scope in the coal wall was obviously reduced. There was no subsided phenomenon of the powered support occurred. The practices showed that the surroundi ng rock control effect of the coal mining face was good.