复杂条件下煤岩体耦合致裂基础研究

Extra-thick coal seam high-efficient fracturing and coal-rock dynamic disasters relief control under the complex conditions are the basis of fully mechanized top coal caving mining. Focus on safety and high efficiency coal-rock fracturing, the coupled-crack is proposed: blasting is done on the weaken coal-rock mass by water injection. From the surface deformation of coal-rock and internal damage, the crack development characteristics are tracked during the process of coupled-crack. The causal link of water/gas conduction and evolution with the crack development is analysed to reveale the coal-rock coupled-crack mechanism at the micro level and give the crack extension criterion induced by coupled-crack. Using the nonlinear dynamic analysis program LS-DYNA, explosive load is obtained and applied to the water injection model so that the dynamic response characteristics of coal-rock is studied to explore the bearing capacity evolution characteristics of model by coupled-crack. For the aim of quantitative evaluation coupled-crack effect, the mechanics model is constructed to equivalent the strength of coal-rock mass after coupled-crack. Through the accomplishment of equivalent discretization transformation for coal-mass overall-dispersion, the rules of top coal caving/flowing pattern and the articulated relationship of discrete state particles and its influence on caving are revealed. The relationship between caving/flowing capacity of coal-rock mass and the parameters of explosive load and injection water pressure is quantified, forming the technology of coal-rock mass coupled-crack and achieving the effect of quantitative assessment caused by coupled-crack in coal-rock mass under the complex conditions.

复杂条件下特厚煤层高效致裂与煤岩体动力灾害的卸压防治是综放开采的基础。为此聚焦于煤岩体安全高效致裂，提出耦合致裂：在煤岩体已被注水弱化的基础上实施爆破。从煤岩表面变形和内部破坏两方面追踪耦合致裂过程中裂纹发育特征，分析水/气传导、演化规律与裂纹发育间的因果联系，在微观层面上揭示煤岩体耦合致裂机制，给出耦合致裂时裂纹的扩展准则。运用非线性动力分析LS-DYNA程序计算获得爆炸荷载并施加于注水后的模型，研究耦合状态下煤岩体的动力响应特征，探索耦合致裂后模型的承载能力演化特性。针对耦合致裂效果定量化评估，构建等效于煤岩体耦合致裂后强度的力学模型。通过完成煤岩体整体–散体的等效离散化转化，揭示耦合致裂后顶煤的垮放流动规律、离散态颗粒间的铰接关系及其对垮放程度的影响，量化装药量、注水压力和煤体垮放能力之间的映射关系，形成复杂条件下煤岩体耦合致裂技术，实现复杂条件下煤岩体耦合致裂效果的定量化评估。

本项目以复杂条件下特厚煤层高效致裂与煤岩体动力灾害的卸压防治为研究背景，聚焦于煤岩体安全高效致裂，提出了耦合致裂。从煤岩表面变形和内部破坏两方面追踪耦合致裂过程中裂纹发育特征，在微观层面上揭示了煤岩体耦合致裂机制，给出了耦合致裂时裂纹的扩展准则。运用非线性动力分析LS-DYNA程序计算获得爆炸荷载并施加于注水后的模型，研究了耦合状态下煤岩体的动力响应特征，探索了耦合致裂后模型的承载能力演化特性，构建了等效于煤岩体耦合致裂后强度的力学模型。通过完成煤岩体整体–散体的等效离散化转化，揭示了耦合致裂后顶煤的垮放流动规律、离散态颗粒间的铰接关系及其对垮放程度的影响，量化了装药量、注水压力和煤体垮放能力之间的映射关系，实现了复杂条件下煤岩体耦合致裂效果的定量化评估，形成了复杂条件下煤岩体耦合致裂理论与方法，在乌东煤矿成功转化应用，有效提高了急倾斜特厚煤层综放面顶煤的回收率、有力的控制了动力灾害发生的频度与规模，实现了矿井的安全高效开采，为类似煤层安全开采提供了科学有效的依据。为类似煤层安全开采提供了科学有效的依据。发表与本项目研究相关的学术论文15篇，其中SCI/EI收录6篇；出版学术专著3部；授权发明专利6项、实用新型专利2项，软件著作权1项，审查中发明专利2项。项目负责人与团队成员获得省级一等奖3项、二等奖1项、厅级奖励1项，研究成果还获得陕西省博士后成果奖励。项目研究期间，项目负责人崔峰晋升为副教授、硕士导师，博士后出站并考核为优秀，入选陕西省“高层次人才特殊支持计划”青年拔尖人才，获聘为中国岩石力学与工程学会软岩工程与深部灾害控制分会理事。培养博硕士研究生10名，出站博士后1名，在站博士后1名。项目组成员参加了10次国际、国内学术交流活动，累计达20人次。