Research On The Optimized Of Safe Mining Parameters By Room And Pillar Method In Hu Jiagou Limestone Mine

China is one of the world’s rich limestone resource countries. At present, there are alarge number of underground limestone mines which are being mined in the country, butpeople exploit and transport most mines by themselves. The mining which has backwardproduction technology is small scale. With the extension of time and with the expansion ofthe exploitation of mining area, original experience to deal with the stress is notcomprehensively considered, resulting in unreasonable stope parameters, which has seriouseffect on the safety, economy and high efficiency of mine production. At present,underground limestone mines in Chongqing are mainly distributed in Dazu, Rongchang andother counties. People exploit limestone resources mainly by the room and pillar miningmethod, hand drill drilling, blasting caving, mini excavator or loader loading ore, usingautomobile transportation in mining area. Most mines produce by retaining limestone layerwith the mining of room and pillar method. Stope structure parameters are very important tothe limestone ore mining. Reasonable stope parameters not only ensure stability roof, whichwon’t result in the occurrence of goaf collapse and surface subsidence and other large-scalepressure activities, but also improve the recovery rate of ore maximum and increase theeconomic benefit of mine.In combination with the actual mining situation of Hujiagou limestone mine in the DazuDistrict and in view of the geological conditions and mechanical properties of the mine rockin Hujiagou mine, theoretical calculations and numerical simulation are used to calculatespan, mining height, diameter and mine pillar column spacing of room and pillar miningparameters stope, and the original mining design parameters are analyzed and compared. Theconclusion is arrived at as follows:Using a theoretical calculation of room and pillar stopes parameters, we can derive10mof stope span,9m of retaining top thickness,10m of pillar and6m of pillar pitch diameter,which is in line with the actual situation and work experience. Applying software FLAC3D, we can simulate stress, displacement and plastic changes zone of surrounding rock and pillarin Hujiagou limestone bord and pillar mining method in the process. From four aspects of themining height, stope span, pillar diameters and spacing, we can obtain6m of mining height,6m of pillar diameter,8m of pillar spacing,10m of stope span. Thus we can ensure the safetyof the premise to maximize the rational exploitation of mining resources. Stope structuralparameter calculation study, theoretical calculations and numerical simulation results areobtained close to the Institute, which is in line with the actual situation of engineeringexperience and field. Comparing with mine stope structure parameters previously used, theresults of optimization study were more favorable mining operations mine, and mine to theinitial application, which better meets the demands of mine production in the safety, economyand benefits.