Research On Mechanical Mechanism Of Ground Stress Effect On Roadway Surrounding Rock Stablity And Controlling Technology In Zhaogu NO.1Coal Mine

Ground stress is the fundamental force, which arouses deformation and failure ofsurrounding rock. With the gradually increasing coal mining depth in our country, a fairlylarge number of mines have entered the high stress area mining, deformation, failure andunstability of surrounding rock are more and more serious by the ground stress.This paper researchs on mechanical mechanism of ground stress effect on roadwaysurrounding rock stablity and controlling technology in Zhaogu NO.1coal mine. Theassociation method of physical and mechanical parameters test, in-situ stress test, rockmechanics theory and numerical simulation are used to analyse and research the problemsystematically, draw the following conclusions:Firstly, two_one coal seam roof lithology is better, floor lithology is weaker in ZhaoguNO.1coal mine. Ground stress test results show that it’s ground stress magnitude is highstress, is σHVstress field, maximum principal stress is nearly horizontal stress, which is theprimary force of arousing collapse and floor heave of east-west roadway.Secondly, analysise stress distribution and stability of circular roadway surrounding rockby using rock mechanics theory, the stability of roadway surrounding rock is closely related toplastic zone distribution range, roadway deformation, stress concentration factors, the anglebetween the axial location of roadway and direction of maximum horizontal principal stress.Analysise the effect of lateral pressure coefficient on choosing roadway axial ratio and stressdistribution rules around roadway.Thirdly, analysise the mechanism of roadway surrounding rock loose circle, tested loosecircle size of prats of the roadway in Zhaogu NO.1coal mine,combined with ground stresstest results, roadway surrounding rock were divided into six categories, and gave advancesupporting programmes for all kinds of roadway surrounding rock.Fourthly, numerical simulate the effect of lateral pressure coefficient and the anglebetween the axial location of roadway and direction of maximum horizontal principal stresson stability of roadway surrounding rocks. Arched tunnel applies in high horizontal stressenvironment, because the stress distribution is more homogeneous, stress concentration androadway deformation are smaller. It causes minor infections on stability of roadwaysurrounding rock when the angle is less than40°.However, sides destruction depth is significantly greater than roof’s and floor’s, moreover, a side deformation and failure aregreater than the another side’s, when the angle is more than40°.Finally, analyse roadway supporting design method based on ground stress and thefactors of affecting deformation and failure of east wing ventilation roadway under theoriginal supporting. After field testing, roadway surrounding rock deformation has beencontrolled effectively after the first supporting with bolt-cable-mesh-shotcreting supportingand the second supporting with long annular compressible closed support along with backwallgrouting combined support technology.