Study on rib spalling cause and control technology of high cutting island coal mining face

According to the spalling and roof falling easily occurred in the high cutting island coal mining face, the theoretical analysis, numerical simulation and sit e practice methods were applied to the study on the spalling and roof falling causes and control technology for the high cutting island coal mining face. The study results showed that the spalling and roof falling of the high cutting coal mining face were not only due to the high stress surrounding rock, large free space, high developed cra cks of the seam and other natural factors, but also were influenced by the low initial support force of the powered support, untimely support and other engineering factor s. A“palm rope+grouting"full length anchoring technology combined with the comprehensive control technology was firstly provided. The technology could make the coa . | seam and the palm rope bound as one body, could obviously improve the self bearing capacity of the coal seam and could enhance the shearing strength and tensile s trength of the coal seam. And the application cost would be obviously lower than the conventional bolt and anchor technology. The numerical simulation analysis was ve rified the control effect of the technology. The technology was successfully applied to the mine site, could effectively control the spalling and roof falling occurred in the coal wall and could provide the experiences to prevent and control the spalling and roof falling of the coal wall in the similar high cutting coal mining face.