Mechanism Of Surrounding Rock Deformation And Failure And Control Method Research In Large Deformation Mining Roadway

Deformation and failure of gateways with large deformation is essentially causedby the formation and development of plastic zone, the different geometry and scopedetermine the failure mode and degree of ground. Based on the engineeringbackground of gateways of Baode Mine, with the comprehensive study methods oftheoretical analysis, field tests, numerical simulation, laboratory tests and fieldengineering tests and from the view of the formation and development of roadwaysground plastic zone, mechanism of ground deformation and failure, and controlprinciples and methods of gateways with large deformation were studied. Theseinnovative achievements were gained:(1) Boundary equations of circle roadwayplastic zone in uneven stress field were derived, butterfly-shaped irregular plasticzone and its formation mechanical mechanism were theoretically found, influencedegree of some key factors, magnitude and direction of stress field, section shape ofroadway, lithological combination etc., to the plastic zone morphology, results oftheoretical analysis, numerical simulation and field detection were consistent;(2)Laws of formation and development induced by mining of the plastic zone weregained, qualitative relevance of plastic zone morphology and ground deformation were built, the mechanism of asymmetry large deformation induced bybutterfly-shaped plastic zone spin around the direction of principal stress wererevealed;(3) Relation of support-plastic zone-ground of gateways with largedeformation were built, the plastic zone and ground deformation was basically given,mainly influenced by mining superposition field, provided support resistance underexisting engineering and technology condition could hardly control the plastic zoneand deformation of ground;(4) Ground control principle of inhibit plastic zonetransfer from steady state into unsteady state were proposed, and developedcooperation support technology of bolt and docking bolt, field engineering testsshowed that, this support technology can adapt large ground deformation, providesustainable support resistance without failure, effective keep the broken rock withinplastic zone stable and prevent malignant expansion.