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1、含瓦斯煤破坏形式与瓦斯突出机理缪协兴1,2、岳建华3、陈占清1,3(1岩土力学与地下工程国家重点实验室(中国矿业大学),徐州;2中国矿业大学理学院,徐州;2中国矿业大学资源与地球科学学院,,徐州)摘要:阐述了含煤破坏形式和流动法则,在此基础上,运用时变边界系统动力学的观点解释了瓦斯突出机制。含瓦斯煤在剪切屈服后,流动是双向的,而在拉伸破坏后,流动是单向的,因此不宜将含瓦斯的破坏及流动用统一的法则表达出来。突出是由破坏引起的煤层边界时变过程;是否发生突出,取决于边界时变过程中瓦斯的运移情况:如果在煤层破坏过程中,裂隙连通、瓦斯可以畅通地运移,
2、则不会在破裂区积聚瓦斯能量,从而不会发生突出;如果裂隙不连通,或者地应力造成裂隙闭合,并且瓦斯压力的自密封作用使多层球壳状的破裂区维持一种具有一定承载能力的结构,则当瓦斯能量集聚到一定限度时,就造成球壳状结构失稳,并发生瓦斯突出。关键词:时变边界系统动力学,瓦斯突出,含瓦斯煤,破坏,流动ThefailuremodesofcoalcontaininggasandthemechanismofgasoutburstMiaoXiexing,ChenZhanqing,YueJianhua(1StateKeyLaboratoryforGeomechan
3、icsandDeepUndergroundEngineering(ChinaUniversityofMiningandTechnology),Xuzhou;2SchoolofScience,ChinaUniversityofMiningandTechnology,Xuzhou;SchoolofEarthandGeoscience,ChinaUniversityofMiningandTechnology,Xuzhou)Abstract:Ontheexpatiationonthefailuremodeandflowruleofcoalconta
4、ininggas(CCG),themachanismforgasoutburstisexplainedbyusingdynamicsofsystemswithvariableboundaries.TheflowofCCGpostshearingsubmittalisbilateralflow,andtheflowposttensionfailureisunilateral,soitisunfavorabletoformulatetheruleofbothfailureandflowofCCGinanidenticalplasticpoten
5、tialfunction.Gasoutburstissuchaprocessinwhichtheboundariesofcoalseamarevariablebecauseofthefailureofcoal.Whethertheoutbursttakesplaceisdecidedbythemigrationofgascontainedinthecoalseamduringtheprocess.Duringthefailureofcoalseam,ifthefracturesareconnectedeachotherandthegasca
6、nmigratefreely,thennoaccumulationofenergyexistsinthefracturedzones,andgasoutburstdoesnottakeplace;Contrarily,ifthethefracturesarenotconnectedeachotherorevenclosedowingtogroundstress,thethefracturedzonewhichtakesontheformofsphericalshellswithmanylayerswillremainacertaincarr
7、yingcapacitybecauseoftheSelf-sealingofthepressureofgas.Whentheaccumulationofenergyofgasachievesalimit,thestructurewithsphericalshellswillbeinstable,andgasoutbursttakesplace.基金项目:国家重大基础研究发展计划(973)2005CB;国家自然科学基金重点项目Keywords:DynamicsofSystemswithvariableboundaries,gasoutburs
8、t,coalcontaininggas,failure,flow煤与瓦斯突出是破碎的煤与瓦斯由煤体内突然向采掘空间大量喷出,是煤矿生产过程中最为严重的灾害之一[1]。从力学上讲,