Study Of Surrounding Rock Structure And Deformation Mechanism Of Roadway Under Different Widths Of Section Coal Pillar

Realize the surrounding rock structure character and the mechanism and law of itsdeformation and destroy exactly is the precondition to control it efficiency. This paper baseson the different lay system and different lay position divide the entry into three different kinds,roadway driving in integrated coal, roadway protected by big coal pillar and roadway drivingalong next goaf. To these 3 kinds of different coal pillar width situations, and combine theactual condition of 2311 full mechanized sublevel caving working face of Cuizhuang coalmine, use 3 kinds of research methods such as mechanics theoretic analysis, numericalsimulation and actual observation on-site analysis the surrounding rock structure character,stress condition and the main stress distributing, plastic zone development and thedisplacement distortion value in the line of strike and side direction. Based on these analysisthe mechanism of the roadway surrounding rock.First of all, based on the distributing law of stress on the coal pillar, considering that theyield of coal and rock class medium is influenced by the volume stress, using the limitingequilibrium theory, Airy stress function and the broad sense Mises yield criterioneducing the plastic zone development depth formula and the critical width formula of elasticrange in the middle of coal pillar. It shows that the development of the plasticity zone is fromtop to bottom, the main reason for the coal pillar's destroy is the stress centralize, and also hasappraised the impact on width of coal pillar of various factors, and calculates the reasonablewidth of the protection coal pillar through the actual situation of 2311 working face at WeishanCuizhuang coal mine is 5.6m. Secondly, use the numerical simulation software analysis thedistributing of main stress, the development of plastic zone and the displacement ofsurrounding rock of different time segment, different coal pillar width. And we design 16models in all, simulate the roadway ground behavior and its surrounding rock deformationdestroy law when the advanced distance of working face is 10m, 20m, 30m, 40m, 50m, 60mand the width of coal pillar is 4m,6m,8m,10m,15m,20m,25m,30m,35m,40m respectively.It shows the reasonable width of coal pillar should between 6m to 8m. Finally, we disposedsurveyed area in the working face to observe, collect and analyze the data of the deformationfield and stress field of coal-pillar and the deformation of roadway surrounding rock. The observation result shows the destroy shape of the small coal pillar is "asymmetry saddleshape".