基于Hoek-Brown 准则的薄基岩厚松散层覆岩变形破坏特征研究

Study on deformation and failure characteristics of overlying strata with thick loose layers and thin bedrock based on Hoek-Brown criterion

  • 摘要: 基于Hoek-Brown准则,以实验数据为基础确定了乌兰木伦矿的岩体力学参数,并运用 FLAC3D 研究了煤层开采引起的覆岩破坏特征。 结果表明:①在浅埋深条件下覆岩破坏直至地 表,地表形成偏态下沉盆地,最大下沉值2.1m,下沉系数0.6。 ②在开采区域四周边界一定范围 内分别形成应力降低区和应力增高区,呈现“外紧内松”状态,在工作面煤壁前方垂直应力集中 程度最高,应力集中系数为2.2,在工作面煤壁上方和开切眼上方均存在“压力拱”,但两者的跨 度、拱脚区域大小及应力集中程度不同。 ③乌兰木伦矿12403工作面垮落带高度为18.9m,导水 裂隙带高度为62.5m。

     

    Abstract: ThemechanicsparametersofrockmassinWulanmulunminearedeterminedonthebasisof theexperimentaldatameasuredinthelaboratoryandappliedHoek-Browncriterioninthispaper.On thisbasis the failure characteristics of overlying strata caused by coal mining are studied through FLAC3Dsimulationsoftware.Theresearchresultsshowthat:①Theoverlyingstrataundershallowburial depth until surface has been destroyed, and the skewness subsidence basin is formed on the
    surface.Themaximumsubsidenceis2.1m,andthesubsidencerateis0.6.②Thestress-relaxedarea andthestress-increasedareaareformedinacertainrangeofthesurroundingboundaryofthemining area.Thestatepresents“externaltightinternalloosing”.Thedegreeofverticalstressconcentrationin frontofcoalwallisthehighest,andthestressconcentrationfactoris2.2.Thereisapressurearchseparatelyabovethecoalwallandtheopen-offcut,butthespan,thesizeofthearchfootandthedegree ofstressconcentrationaredifferent.③Theheightofthecavingzoneis18.9m,andtheheightofwater flowingfracturedzoneis62.5mof12403faceinWulanmuluncoalmine.

     

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