Roof gap rationality research of backfilling coal mining hydraulic support

For roof gap of backfilling-coal mining hydraulic support significantly affecting compression ratio and backfilling operation efficiency,authors revealed its existence mechanism,which were structural interference leading to theory roof gap and site operation leading to actual roof gap.According to these two mechanisms,authors analyzed two design theories of reasonable roof gap from structure optimization and different compression ratio requirement respectively,proposed the sensible design standard that the designed roof gap must meet this two theories at the same time,i.e.,the accumulated quantity by backfill operation strictly controlled by roof gap should be no less than the quantity required by different compression ratio(namely V zj ρ1 ≥V z ρ2).With machinery automation simulation software Pro/E 5.0,simulated and analyzed the change law between mining height and roof gap value for dimensions given hydraulic support,based on simulation curve,divided compaction ratio assurance area for this hydraulic support,judged its design and pros and cons of mechanism optimization.Eventually formed a judgment method and inspection standard for reasonableness design of hydraulic support based on index of roof gap.