Grouting Reinforcement for Broken Roof in Return Air Roadway With Large Inclination Mining Face

According to 25221 working face of coal roadway and mining uncovering situations in 2130 Coal Mine, due to the high strength of roof strata, it needs forced caving. This leads to the crush of triangle top coal which is close to the working face upper return air roadway, and the weak stability of top coal; the collapse of top coal leads to the tilt of hydraulic support. With the chemical grouting and reinforced technology for the coal and rock masses, the stability of the coal and rock mass was improved and the roof accidents due to the coal wall spalling was eliminated, which had ensured the successful mining operation of the coal mining face.