摘要:
为解决松软煤体爆破孔成形困难导致深孔预裂爆破技术无法应用的问题,选择在运输巷底板距煤
层较近的岩石中进行爆破,利用数值模拟方法进行了相关理论探讨。分析了煤岩介质和单煤体介质中布孔的
差异,建立了单煤体和煤岩体深孔预裂爆破的5个数值计算模型。研究了单煤体和煤岩介质爆破孔与抽放孔
连心线上有效应力随距离的变化,从岩孔爆破传播到煤层其应力衰减的程度较单煤层中大得多,但在靠近抽
放孔附近煤层,二者的差距变小。抽放孔轴线方向所受有效应力的大小是决定爆破效果的重要因素,煤岩介
质中爆破孔与抽放孔间距为2.0m 时,抽放孔轴线方向上的平均有效应力与单煤层中爆破孔与抽放孔间距
为3.0m 时的相当,可作为实现岩孔爆破效果的布孔参数。
关键词:
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爆炸力学 /
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动态应力 /
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计算模型 /
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煤层 /
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岩石 /
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爆破
Abstract:
Toovercomethedifficultyinusingthedeep-holepre-splittingblastingtechnologyinthesoft
coalseamspronetoresultingintheboreholecollapse,anewmethodwasappliedtoincreasingthegas
drainagerate,inwhichtherocknearbythecoalseamwasexplodedatthebottomofthelaneway.The
theoriesforthetechniquewereexploredbynumericalsimulation.Layoutsofblastholesanddrain
holeswerecomparedthesinglecoalseam andthecoal-rock media.Fivenumericalcomputational
modelswereconstructedbyDYNA3D,includingasinglecoalmodelandfourcoal-rockmodelswith
thedifferentdistancebetweentheblastholeandthedrainhole.Thecorrespondingeffectivestress
wascomputedalongthelinkinglineoftheblastholeandthedrainhole.Thecomputationalresults
showthattheattenuationoftheeffectivestressfromtheblastholetothedrainholeismoreinthe
coal-rockmediathaninthesinglecoal,whereastheeffectivestressdifferencebetweenthetwomedia
decreasesinthecoalseamsadjacenttothedrainholes.Thedistributionoftheeffectivestressalong
theaxisofthedrainholeissignificanttothedraineffect.Themeaneffectivestressalongtheaxisof
thedrainholeincoal-rock media,whenthedistancebetweentheblastholeandthedrainholeis
2.0m,isappropriatelythesameasthatinthesinglecoalseam,whenthedistancebetweentheblast
holeandthedrainholeis3.0m.Anditcanbeusedasthelayoutparametertokeepthesameblast
effectinthecoal-rockmediaasinthesinglecoalseam.
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