摘要:
以汾西矿区南关矿煤巷为原型,依托嵌套式相似模拟实验系统建立物理相似模型,研究 煤巷在钢管混凝土支架支护下围岩应力、位移分布规律和变形破坏特征。 应用FLAC3D5.0建立 钢管混凝土支架巷道模型,分别模拟埋深100~1000m的情况,分析煤巷变形破坏规律及支架受 力特点。 研究结果表明:钢管混凝土支架能提高巷道的径向支撑压力,加载初期保持了巷道稳 定,但随着荷载加大两帮收敛量大于顶底板移近量,帮部先出现裂隙并向顶底板发展,随后帮部 和顶板相继失稳,可见帮部是支护的薄弱环节。 在钢管混凝土支架作用下,巷道表面应力呈锯齿 状分布,说明支架对围岩存在有效支护范围,支架之间是支护的薄弱部位;支架套管的轴力和弯 矩均较大,容易发生破坏,导致支架的承载力丧失。 可见,控制煤巷帮部和支架套管的变形破坏, 提高其强度,是保证南关矿煤巷钢管混凝土支架支护稳定性的关键。
Abstract:
TakingthecoalroadwayinNanguanmineofFenximiningareaastheprototype,relyingon thenestedsimilaritysimulationexperimentalsystem,thephysicalsimilaritymodelwasestablishedto studythestressdistribution,displacementanddeformationfailurecharacteristicsofthesurroundingrock ofcoalroadwaysupportedbyconcretefilledsteeltubesupport.FLAC3D5.0softwarewasusedtoestablishthecalculationmodelofconcretefilledsteeltubesupportroadway,whichsimulatedthedepthof 100mto1000mrespectively;thedeformationandfailurelawofcoalroadwayandthecharacteristicsof supportstresswereanalyzed.Theresultsshowedthat,concrete-filledsteeltubesupportcanimprovethe radialsupportpressureofroadway.Attheinitialstageofloading,thestabilityofroadwayismaintained, however,with the increase of load,the convergence of sidewall is greater than that of roof and floor.Fissuresfirstappearinthesidewallanddeveloptotheroofandfloor,thenthesidewallandthe roofareunstablesuccessively.Itcanbeseenthatthesidewallistheweaklinkofsupport.Undertheactionofconcretefilledsteeltubesupport,thestressdistributionontheroadwaysurfaceisserrated,which indicatesthatthesupporthasaneffectivesupportrangeforsurroundingrock,andthesupportbetween thesupportsisalsotheweakpartofthesupport.Theaxialforceandmomentofthesupportcasingare larger,andthecasingiseasytobedamaged,whichleadstothelossofthebearingcapacityofthesupport.ItcanbeseenthatthekeytoensurethestabilityofconcretefilledsteeltubesupportinNanguan mineistocontrolthedeformationandfailureofsidewallandsupportcasingandtoimproveitsstrength.
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