| The surrounding rock mass quality of roadway affects the stability and safety of mine roadway engineering,which gets more complicated in the areas of tectonic stress concentration.The roadway deformation and support damage are seriously in Jinchang minging area of Yinan gold mine,where is more influenced by the concentrated tectonic stress.It is necessary to further study the stability of surrounding rock in roadway.In this paper,taking the typical roadways in Jinchang mining area as the research objects,the stability evaluation method of roadway surrounding rock suitable for the areas of tectonic stress concentration is studied by means of field observation,theoretical analysis,laboratory test and numerical simulation.In this paper,the lithologic distribution range,surrounding rock integrity,rock mechanical properties and hydrogeological conditions of typical mine roadway are found out through engineering geological survey.Through the analysis of the distribution law of the structural fissures and ground stress in the mining area,the geological characteristics of the tectonic stress concentration in Jinchang mining area are clarified.The existing support system of mine roadway is summarized by observation and evaluation of roadway deformation and support failure.The unfavorable factors of the roadway stability in the study area were determined through the analysis of the engineering effect of the mine structure,and the measures to deal with each link of roadway "dig-evaluate-support" in the area where tectonic stress is concentrated was proposed.Based on the application and research of BQ,RMR and IRMR methods,the J-IRMR roadway surrounding rock stability evaluation method was established and optimized by means of multi-section fitting,method fusion,weighted average,hypothesis verification and sublevel refinement.Defined the multi-section fitting functions and tectonic stress correction coefficient of J-IRMR,improved the quantitative analysis degree of the method.Expanded the scoring range of RMR,refinding the five-level classification into five main level and nine sub-classification,refinding the level of ????? into the sublevel of ?-???-???-???-???-???-???-?.The application and comparison of the method of BQ with J-IRMR and FLAC3D numerical simulation of roadway stability verified the applicability of J-IRMR method and sub-classification of five-level system to the tectonic stress concentration area in Jinchang mining area.Synthetically evaluated the overall stability of the roadway surrounding rock in the mine area is bad,most sections of roadway in the area are below grade ?,and the rock body quality changed obviously in difference lithologic roadway,the higher requirements are put forward for differential support methods in roadways.The classification differental support table and special support suggests for J-IRMR method were established by theoretical calculation and hierarchical set of the combined bolting and spraying support,optimized the typical roadway support measures in Jinchang mining area.Justifying the rationality of the roadway bolt parameters different settings in different rock mass quality by the way of FLAC3D numerical simulation of roadway support. |
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