Study On Control Technology Of Surrounding Rock In Roadway Driving Along I010908 Working Face Of Qipanjing Coal Mine

Aiming at the geological conditions of No.9 coal seam in Qipanjing Coal Mine,based on the theoretical calculation of mechanics along goaf,numerical simulation of internal stress in different pillar widths and failure characteristics of surrounding rock of roadway,the process of roof coal seam structure breakage,stress distribution,deformation and failure characteristics and evolution law of plastic zone in I010908 working face are further analyzed.Reasonable pillar width and surrounding rock control scheme of gob-side roadway driving in I010908 face are obtained.The main results are as follows:(1)Analyzing the structural characteristics of overburden strata on working face,the width of protective coal pillar is determined to be 4.07 m by theoretical calculation.The numerical simulation further analyzed the variation law of horizontal and vertical supporting stress on both sides of the return air chute,the range of increasing area,the horizontal and vertical displacement field of surrounding rock along the chute,and synthetically determined the reasonable width of coal pillar to be 6m.(2)The vertical stress distribution,peak stress variation law and plastic zone evolution law of surrounding rock when 6m coal pillars are set up in goaf driving stage are studied.Further analysis is made on the distribution range of deformation peak value in front and stress peak value in both sides along with the advance of the working face in the mining stage,and its influence on the deformation of the solid coal side.With the increase of advance distance,the range of plastic zone decreases and the deformation of surrounding rock decreases,which verifies the rationality of6 m coal pillar.(3)The mechanism of bolt-anchor support is analyzed.On the basis of simulating and analyzing the pre-stressing diffusion law of surrounding rock along the return air groove in I010908 working face under different bolt support parameters,the supporting parameters of return air roadway in I010908 working face are determined.The field application results show that the deformation of surrounding rock is effectively controlled.