Stability control mechanism and integral supporting technology of roadways with thick compound roof strata

摘要

With the increase and extension of coal mining height, common anchor-net-sprouting method is difficult for the country rock stability with thick compound roof strata and big section of gob-side roadways. Through the survey and analysis for lots of compound roof incidents, the destabilizing mechanism and control design were obtained and an in-situ instance of mining support was carried out in 4312 belting crossheading of Xuchang Mine. Good support effect was gained. Research results show that, in order for preventing the occurrence of roof separation and vertical cranny, anchorage cable can be applied for the decrease of span length of roof beam and anchoring the roof compound rock beams with high strength and prestressed anchorage cable while anchor rod is implemented for the increase of integral bending stiffness; in these ways, the bending stress of roof rock beam can be decreased effectively. Composite support of high strength and prestressed anchorage-cable-strap-ladder can satisfy rock stability of thick compound roof and big section of gob-side roadway.