近距离煤层群上保护层开采卸压机理及瓦斯抽采技术研究-采矿工程专业论文

tributioncharacteristicsofoverlyingstrata15图2-8保护层底板应力分布特征16Figure2-8Stressdistributioncharacteristicsoffloor16图2-9保护层底板应力分区16Figure2-9Stressdistinctcharacteristicsoffloor16图2-10保护层上覆岩层裂隙发育特征17Figure2-10Fracturesdevelopmentcharacteristicsofoverlyingstrata17图2-11裂隙演化过程18Figure2-11Evolutionprocessoffrcture18图2-12下伏岩层裂隙分布及分带18Figure.2-12Fracturedistributionandzonationofunderlyingstrata18图3-1煤层的透气性系数变化20Figure3-1Variationcurveofgaspermeability20图3-2被保护层透气性变化特征21Figure3-2Gaspermeabilityvariationcharacteristicsinprotectedlayers21图3-3被保护层卸压瓦斯的运移22Figure3-3Pressurereliefgastransportinprotectedlayers22图3-4采动裂隙内瓦斯的运移与储集23Figure3-4Pressurereliefgastransportandenrichmentinmining-inducedfractures23图3-5沿煤层工作面走向的底板塑性破坏区24Figure3-5Theplasticfailurezoneofflooralongcoalseamstrike24图3-6上保护层工作面沿倾斜方向的保护范围26VII