Observation of Coal Mine "Three-soft" Formation Roadway Rock Pressure and Secondary Supporting Reserved Amount Determination

Through a comprehensive understanding of Shandong Longkou Mining Area geological conditions, we learned that this mining area is a typical "three soft" formation. According to the characteristics of the "three soft" formation, the laws of roadway deformation are obtained by mine pressure monitoring and laws analysis, then a reasonable reserved amount of pressure release space of secondary supporting is determined. The secondary support steel will be protected effectively, the failure rate of roadway will be lower and the cost of roadway support will be cut down. The cost will be cut down on the premise that the safety can be guaranteed.