Reasonable layout and application of inner dislocated gas roadway at the first mining working face with high gas mine

Abstract

Taking supporting force,deviatoric stress,surrounding rock deformation,and plastic zone as the analysis points,numerical simulation,geomechanical model test,borehole imaging methods were utilized to solve the difficult problem of transfinite gas phenomenon during excavation of mining roadway at the first mining working face of high gas mine,and the reasonable layout of the gas roadway was determined.The results show that the deviatoric stress can reflect the resistance to yield deformation of surrounding rock well; the evolution law of deviatoric stress matched well with characteristics of supporting force,surrounding rock deformation,and plastic zone.When the horizontal space is from 6 m to 8 m,the anchorage bolt can exert long-term bearing capacity effectively,and the resistance to yield deformation capability of surrounding rock is strong.So the permeability of surrounding rock is very good.The range of distribution fissure in roof is from 0.5 m to 3.5 m,while the left side is from 0.5 m to 2.6 m.The distribution characteristics of fissure in roof of roadway and side coal mass from borehole observation are similar with results from numerical simulation and geomechanical model test.Field application shows that 8 m horizontal roadway spacing can ensure the stability of both lanes,improve the gas drainage efficiency and satisfy the requirements and efficient production.

Keywords

• high gas mine
• deviatoric stress
• geomechanical model test
• borehole imaging