DOI: 10.11799/ce201711001
Study on fully mechanized top-coal caving technology for ultra-soft extra-thick coal seam with high gas and hard roof
PAN Wei-dong
NIE Xiao-dong
LUO Jian-yang
Abstract：In view of the complex mining technical conditions of the 828 fully mechanized top - coal caving face in Qingdong Coal Mine, a mining plan was put forward to pre-mine upper No. 7 coal seam to control the hard roof and gas of No. 8 coal seam. Using the K. Terzaghi theory, the failure depth of coal seam floor was analyzed, and the hard roof caving interval was analyzed using Rock Beam Theory. Based on the physical material similarity simulation, the overlying strata movement rules with and without the pre-mining of No. 7 coal seam were analyzed. Working resistance of the hydraulic supports was analyzed through field test. The results showed that failure depth of 726 working face floor was 13. 8 m, and the thickness of undamaged hard roof was 5. 3m. Fracture interval of the hard roof shortened from 24. 9m to 10. 6m after the pre-mining of No. 7 coal seam. The similar material simulation results showed that caving interval of hard roof in No. 8 coal seam shortened from 20m to 10m after the pre-mining of No. 7 coal seam. In the actual production process, the hydraulic supports worked effectively, the initial weighting interval was 20. 4m, and the periodic weighting interval was 10. 4m. The results showed that pre-mining upper No. 7 coal seam solved the hard roof and gas problems in the mining of 828 working face.
Keywords：hard roofextra-thick coal seamfully mechanized top-coal cavingphysical material similar simulation
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 1-6 )