Study On The Deformation Mechanism Of Water-rich Coal Roadway Of Xiaojihan Coal Mine

The significant hidden danger of coal mine safety production is restricted by water disasters. During roadway excavation, its surrounding rock expansion as absorbing water, leading to the strength weakening and deformation intensified. For the more, Deformation of surrounding rock of roadway could be aggravated by the change of the section size of tunnels and underground drain drainage. Xiaojihan mine water-rich coal seam is the first time founded and as the main confined aquifer. On this special hydrogeological engineering background, research on roadway deformation mechanism of water-rich coal seam to guide the mine safety production has important theoretical and practical significance.The main research contents and results of this paper are as follows:(1) In view of the conditions of the mine roadway floor, field sampling of floor rock mineral composition and the action of rock swelling, systematic experimental research on rock strength weakening under water. We found that montmorillonite, illite and other swelling minerals contain in rocks is micro influence factors of deformation of surrounding rock, floor rocks under the action of water to produce high expansion stress and macro surrounding rock deformation. Giving the silty mudstone of roadway floor tensile strength, uniaxial compressive strength and elastic modulus weakening rule function change with moisture content and different soaking time.(2) Use rock elastic-plastic mechanics knowledge, considering the rock strength attenuation and strain softening characteristics, theoretical research on the radius of plastic zone and deformation characteristics of surrounding rock of roadway. Given analytic expressions the radius of plastic zone of surrounding rock, stress of any point within surrounding rock, displacement of surrounding rock of roadway surface. Compared with under no water action, the radius of plastic zone increases obviously, the surface disp lacement of surrounding rock of roadway increases with increasing degree of rock softening.(3) Establish the numerical model of roadway surrounding rock under different moisture content condition, FLAC3 D numerical analysis strength weakening characteristics of surrounding rock during roadway excavation with the increase of water content. Simulation studies of roadway surrounding rock stress and strain, plastic zone distribution and deformation of surround ing rock surface. Found that the deformation of surrounding rock increase with the increase of moisture content of rock, and reveals basic deformation principle and rule of water-rich coal seam roadway surrounding rock.(4) Combine with engineering practice of Xiaojihan coal mine roadway surrounding rock characteristics, Analysis the factors that influence the deformation of surrounding rock for underground water softening of floor rock strength and expansion of surrounding rock under water.With xiaojihan water-rich coal mine as the research object in this paper, research results applied to engineering design and construction of the field. Show that water-rich coal seam roadway deformation mechanism study is of great significance to the mine safety production.