Study On Failure Mechanism And Supporting Technology Of Floor Roadway Under Mining Influence

With the increasing depth of coal mining, the number of roadway under curving influenceis progressively. While support of curvingeffect roadway has been the major challengein themining sector, the study on deformation failure mechanism and supporting technology has animportant theoretical and practical significance. The thesis relies on the project of“Surrounding Rock Reinforcement Technology Research of Floor Roadway under MiningInfluence”, analysedthe failure mechanism of floor roadway surrounding rock undermininginfluence, proposed the supporting scheme which well applied in engineering practice.Through the combination of laboratory and field experiment, the deformation failureoffloor roadway surrounding rockis due to the high bearing pressure of overlying seamcurving, furthermore theweak rockstrength,unreasonable supporting scheme andcomplicatedgeological condition are all caused an influence to the surrounding rock stability.Based on the mining pressure theory and elastic theory, the stress distribution of miningfloor has been established and simplified, analyzed the stress distribution under differentdepth. Based on the bidirectional stress solution of infinite plate, there is always acircumferential extreme stress located in the middle of roof, sides and floor.While consideringthe curving effect, the circumferential stress distribution of roof, floor, sides and thedeformation displacement of sides has been achieved.Discussed the mechanism of “spray and bolt, anchor cable” support scheme whichapplied in surrounding rock roadway, analysedthe necessity of floor anchor cable in theroadway under high bearing stress, and proposed a compressibility bearing plate to adjust the“high stress with finite deformation”requirement.Applied the FLAC3Dto simulate the influence to the roadway stability which caused bythe mining procedure, the results show that the circumferential stress of sides increased muchsubstantial than roof andfloors’. The firstfailure appeared at sides, while the working faceadvancingright above the floor roadway，the failure is aggravation by the shear stress, finallyroof and floor isbrokenby the increased hanging length.Applied the FLAC3Dto simulate the four different support scheme, the results show that“spray and bolt”support could just maintain the stability of sides, while cable can fully arousedeep surrounding rock bearing capacity，achieved the overall stability of roadway. Floor cablegives a high support resistance which not only controlled the floor deformation, but alsoimproved the stability of roof and sides.Joint support technology has been applied in engineering practice, through the monitoringand analysis of surrounding rock displacement, the results show that the supporting schemecan effectively control the deformation of roadway and maintain the stability of roadwaysurrounding rock.