The Research On Supporting Technology Of Coal Roadway In Unstable Coal Seams With "Weak-Roof-Coal-Floor" Of Shihuatian Coal Mine

The recovery roadway in unstable coal seam of Shihuatian Coal Mine, Guizhou YunengMining Industry Co.Ltd needs barringdown or floor dinting along with various trend anglesand thicknesses of coal seams, the production and safety of the coal mine were limited bymany fractors, such as the abutment pressures and tectonic stress, the expansion pressurewhich would result in more diffcult supporting there. Uunstable coal seam with weak-roof--coal-floor would be easily roof falling and coal wall caving being nonbenefical forsupporting in tunneling, which troubled construction safety of mining expansion and led tocontinued delays of mine production in beginning period. It follows that supporting problemsin unstable coal seams with weak-roof-coal-floor would be resolved. The gateway (headgateand tailgate) with “weak-roof-coal-floor” used for the No.11071coal mining face which isthe first fully-mechanized coal working face in unstable coal seams is studiedcomprehensively. Tunneling process, we often encounter serious roof fall, wall caving,heaving floor, support is difficult, and maintenance difficulties. With the gateway increasinglength tunneling, tunneling extension of time, the problem of supporting will become moreprominent.On investigating and analyzing the real supporting conditions of unstable coalseam in Shihuatian Coal Mine.Through researching into the surrounding rock’s fundamental mechanical properties ofthis roadway, this thesis put forward an conclusion, which is about the surrounding rock’scharacteristic derived from coal and rock sample mechanics testing. This thesis also resultsthe inherent technical difficulties points of roadway surrounding rock, which show that thesupporting parameter of Shihuatian Coal Mine is influenced by the seam of coal and methane outburst, friable property of “weak-roof-coal-floor”,excavation by drilling and blasting andformer supporting method, outburst prevention and control measures. Then five differentsupporting schemes are studied on according to the different geological characteristics andsupporting reinforcement requirements. On utilizing the3D loading physical simulationtesting device, this thesis completes the analyses of displacement and destruction laws, thecharacteristics of internal distortion variations and surface dislocation changes. Thedisplacement and destruction laws, which are under the environment of dynamic loading, areabout the overburden stratum and about the surrounding rock’s damage and evolution. Afteranalyzing the validity of supporting schemes with FLAC3D, this thesis draws a naturalconclusion that the combination supporting technology of grouting bolt and wire mesh withsteel strip additional big bolting washer and framed roadway support is the most effective wayto support the roadway in unstable coal seam with “weak-roof-coal-floor” of Shihuatian CoalMine, and has been successful practiced the engineering application.This thesis will play an important role in controlling the coal roadway in unstable coalseam with “weak-roof-coal-floor”, and have referential significance of surrounding rockcontrolling and entry supporting with similar geological characteristics.