Mechanical Analysis On Instability Of Deeply Inclined Thin Layer Roof Roadway Surrounding Rock And Support Technology

Tiela Haoyuan mine in Xinjiang mining mainly B9coal seam, the typicaldistance seam group, dip a larger range of40oabove the local average angle of28o,B9, B10seam spacing0.11~29.11m, showing roadway roof board structure, roofcollapse risk, high coal spalling side severely damaged, causing a great impact onproduction safety of the mine.In this paper, the engineering geological conditions above background, theestablishment of a large angle layered roof mechanical model based on the elastictheory, the ultimate roof span, subsidence. Pointed out that the coal of the side crackunder normal compression loads for the wing crack, spall plate structure formed toconstruct models strut lateral buckling, obatin the coal side compressive shearinstability characteristics. FLAC3Dsimulation using large dip layered roof roadwaydeformation damage law, based on the principle anchor synergistic enhanced control,forming a high-performance pre-tension cable bolt support technology system. Andapplied to engineering practice, and achieved good test results, the main results are asfollows:(1) Establish a layered roof clamped at both ends of the "rock beam" model, thecentral roof anchor sector pulled into the roof damage as a basis for defininginstability, elasticity theory solved roadway damage limit width a, obtained criticalstress σcrroof instability, noting that the relationship between the critical stress its roofgeometry and mechanical parameters, is inversely proportional to the square acrossthicker than the critical stress σcrand rock, are sensitive to factors that influence thestability of the roof.(2) Root damage theory based on analysis of the open type, intensity factor sliptype crack tip stress fields tearing-type three models K. the Coal side undercompression loads, the crack is generally split into a wing crack structure (slip plane),injury to help the side rock on the continuum damage into local damage, spall platestructure formation. Establish strut lateral buckling model to study the structure of thespall plate buckling lateral bending the law.(3) Based on the principle of integral and collaboration support, forming a bigdip layered roof roadway overall high performance pre-tension cable bolt supporttechnology collaboration system, the key technology is a high-performance roofpre-tightening cable, the bolt truss of high side, the anchor beams of the zone of near the roof and the side, symmetrical anchor support high side and low side, forming ahigh-performance pre-tension cable anchor overall cooperative control technologysystem.(4)Using FLAC3Dsimulation test using roadway deformation and failurecharacteristics, with significant asymmetry, leading the side to help the high pressureside suffered much greater than the short side. No amount of support were closer torock dome93.2mm, the low side to41mm, the high side is90mm, bottom145mm;then bolt anchor support, the amount was closer to rock dome68.9mm,35.7mm to thelow side, high side57mm, bottom90.0mm, maintenance of effect is obvious.(5) Designed Haoyuan coal transportation laneway904program, effectivecontrol of the roadway deformation. Same roadway support in the same strength,Anchor network support with the cable care compared to the cost of materials of theunit length (by11#steel miners to calculate) frame roof support costs droppedsubstantially1000diversity, efficiency significantly.