Study On Anchoring Quality And Rebar Deformation Characteristics Of Resin Bolts

In order to solve the problems when using resin anchoring agent in coal mine roadways, like excessive stir, oversize holes etc, tests on anchoring quality have been conducted in the laboratory, the effects of stirring time, circular thickness of anchoring agent, and different rebar shapes have been analyzed on anchoring quality. When using medium-speed anchoring agent and the length of anchorage part is125mm, conclusions are drawn that appropriate mixing time is2.5-15s, circular thickness of anchoring agent should be3-4mm, and left-handed anchoring bolt without longitudinal reinforcement anchors best.This study chooses tipical roadways with large deformation as the subjects, observes deformation shape of exposed bolts by side cutting and roof cutting. On site bolts’ deformation feature and mechanism of the above two are analyzed by FLAC3D, a numerical modeling software. Conclusions are drawn that transverse diastrophism of bed plane will cause obvious shear deformation of bolts, and exerts concentrated shear load on bolts.On this basis, the effects of surrounding rock structures and strength, pretension force value of bolts, approach of anchoring, combination support of bolts and cables, have been analyzed on bolt deformation. The results suggest that joint surface is the most liable to diastrophism when the strength of rock stratums differs much and the weak one located below; the deformation can be effectively reduced by full length anchoring, combination support of bolts and cables and high pretension force support.