Abstract The deformation characteristics of surrounding rock after excavating and supporting of coal roadway with great-thick mudstone roof,its failure mechanism and its controlling countermeasures are systematically researched through field investigation,laboratory test,numerical testing,similar simulation and theoretical analysis. Meanwhile these methods are used to represent dynamically the process of rock deformation and failure in the roadways,and the roadway?s behaviors including deformation characteristics,failure mechanisms,stress distribution in the surrounding rocks and the effects of various support systems on roadway stability are studied. Some conclusions can be drawn as follows:(1) The fracture,cracking and separating layer of the thick mudstone roof occurred and promoted promote by two ways,such as the weathering,disintegrating,disruption,dilatancy of the mudstone,as well as the concentrated tensile stress and shear stress in the stress adjustment. (2) Based on the study,it is shown that the original supports in the absence of accurate judgment of the surrounding rock result in the roadway destruction and the supports system abated. (3) The principles to support the mudstone roof are enclosing in time,enhancing the stiffness of the lower rock layer of the roof and disposing the anchor cables along the cracks. (4) Based on the geological mechanics and environmental conditions of the roadway surrounding rock,an optimized roadway support design is provided that effectively avoid the multiple recondition by changing the cross-section and modulating the support parameters. The long-term stability of the thick mudstone roof had been realized. After several successful engineering practices,research results have been adopted in Qipanjing mining area;and the results have great theoretical and practical values to similar roadway supports.
|
Received: 25 June 2010
|
|
|
|