Research On The Stability Of Roadway Of Narrow Pillar And Grouting Reinforcement Tecnique

With the continuous development of coal mining technology, fullymechanized caving mining can be used in working face often. In order toimprove the utilization of coal resources at the same time, the roadway on bothsides of the narrow coal pillar commonly used protective coal pillar. Narrowcoal pillar on the one hand can improve the resources recovery rate, avoid thewaste of resources. But on the other hand it faces pressure in coal face periodicunder the action of continuously, deformation of roadway, obviously, it difficultto support. Under many conditions, the narrow pillar extraction full-mechanizedcaving mining face roadway support research is very necessary.According to theresearch on working surface by caving rule and rule of mine pressure appearanalysis, and combining with the actual working face the measurements of themine pressure regularity and the theoretical calculation of narrow coal pillar size,and by means of FLAC3Dnumerical simulation technology to simulate thedifferent changes of stress and displacement under the condition of narrow coalpillar. Under the condition of determination of narrow coal pillar size, throughthe analysis of narrow coal pillar broken rock grouting reinforcement technology,grouting reinforcement parameters, and finally determined, narrow pillarextraction roadway anchor reinforcement scheme and injection parameters.This article mainly aims at San Yuan coal company coal narrow pillarextraction of full-mechanized caving mining face roadway technology research,the main conclusions are as follows:（1）Based on the working plane caving characteristics of overburdenstratum analysis and combining with the mine pressure regularity of the working face observations return air along the trough in the extraction process of1308face surface displacement and deep displacement are controlled in a reasonablescope, anchor-net supporting effect is good, can ensure that the roadway withinthe service life of the normal use; Return air along the trough of1308face in theworking face advancing deformation speed of50meters scope, anchor cable,anchor force is bigger, should pay attention to strengthen the support and controlits deformation;1308face protection coal pillar abutment pressure peak areaoutside the6.5m, according to the width of coal pillar of tunnel to determinerequirements, can be design within6m width of coal pillar; Roadway drivingalong goaf decorate a face when the return air along the trough, roadway sectionshould step up, to prevent the roof subsidence, two large amount of help nearerinfluence production; Lengthen bolt, anchor cable length and increase its density,guarantee of roadway surrounding rock as an anchor whole;1310working faceof small coal pillar width should be controlled within the range of6meters.（2） By FLAC3Dnumerical simulation software to establish model,simulated the distribution during the excavation and stopping pillars yield failurecharacteristics of surrounding rock, the stress distribution characteristic in thenarrow coal pillar, the displacement distribution characteristics and the influenceof coal pillar width on roadway deformation, and determine the reasonable ofnarrow coal pillar width is5.0m.（3）Through the broken rock grouting reinforcement mechanism, groutingreinforcement mainly has the following features: slurry curing network skeleton;Filling pressure increased the strength of surrounding rock; Reduce broken zoneof roadway surrounding rock; Grouting water curing closed; To improve boltstress state. Combined with the practical geological situation determines thegrouting reinforcement parameters.（4）By analyzing the support plan and parameters, ultimately determines theextraction tunnel support scheme selects the anchor net+steel beam+anchor cable reinforcement of reinforced beam combined support; Roof bolt, anchorlength is2.4m, spacing is900mm, from800mm, anchorage length is1200mm,the top anchor cable, anchor cable length is8m, anchorage length is1800mm,anchor cable row spacing of2.4m, help anchor rod, anchor length is2.4m,anchorage length is600mm.