摘要:
在岩石爆破理论的基础上分析了煤体中爆炸应力波的作用机理,借助损伤力学理论探讨了煤体在
爆炸应力波作用下的损伤断裂准则。煤体中爆炸应力波传播与衰减规律模拟实验结果表明:煤体中爆炸应力
波一般包含2段波形,第1段由压缩相和拉伸相组成简单波形,第2段是由多种作用形成的复杂波形;爆炸应
力波作用下,煤体首先承受压应力,而后承受拉应力,且压缩相的作用时间较拉伸相作用时间短;煤体中爆炸
应力波的衰减速度较一般岩体中的快,实验条件下应力波衰减因数符合=3-/(1-),爆炸应力波的主要
作用是在煤体中形成少量新裂隙、激活煤体中原生裂隙并打破煤体中瓦斯气体的平衡状态。
Abstract:
Basedonthetheoryofrockblasting,theactionmechanismofexplosionstresswaveincoal
wasanalyzed.Thedamagefracturecriteriaforcoalsubjectedtoexplosionstresswavewasexplored
accordingtothedamagemechanicstheory.And,simulationexperimentswereconductedtoobtainthe
attenuationlawofexplosionstresswavepropagationincoal.Theexperimentalresultsshowthatthe
stresswaveateachmeasuredpointcontainstwoormorewaveforms,therearecompressionphaseand
tensilephaseinthefirstwave,thewaveformofwhichissimpleandsmooth,andthesecondwaveis
theresultofavarietyofaction,thewaveformofwhichiscomplex;thatthecoalmediaisfirstunder
compressivestressandthenundertensilestress,theactiontimeofthecompressivestresswasshorter
thanthatofthetensilestress;andthatthedecayrateofexplosionstresswaveincoalisfasterthanin
generalrock.Themaineffectsofexplosionstresswaveincoalconsistofformingasmallnumberof
newcrannies,activatingthenativecranny,andbreakingthebalanceofcoalgas.
下载: