覆岩离层水涌突模式与机理研究

Study on roof bed separation water disaster which is a new type of coal mine water disaster and doesn’t attract people's enough attention. Analyzing overburden rock structure before coal mining, rock structure variation due to coal mining and characteristics of the bed separation water disasters, three water inrush patterns are put forward, including "dynamic water-inrush due to high-position roof breakage", "hydrostatic water-inrush" and "periodic pressure water-inrush" patterns. Through impact proneness test of rock stratum, anti-bending test, closed water impact water pressure test, the rock plate breaking microseismic characteristics of physical simulation, mining and rock impact failure effect numerical simulation experiment and simulation methods to study the process mechanism of "dynamic water-inrush due to high-position roof breakage". Unloading triaxial permeability test will carry out considering bed separation water seepage pressure and mining disturbance. The theoretical analysis and numerical calculation of seepage- stress - damage coupling will reveal the form mechanism of hydrostatic water-inrush channel. To carry out separation " periodic pressure water-inrush” of flow solid coupling physical model experiment and numerical simulation, analysis of mining disturbance under the main roof / inferior key strata cycle of broken fault induce abscission water outburst multi-field information evolvement characteristics and rules, reveal the inherent mechanism of water inrush. The proposal presents the 3 inrush modes of bed separation water，gives its occurred conditions and reveals its disaster mechanism. It has great significance to enrich technology and theory of water disaster control, and guide coal mine safety production in hard roof and deep mining practice.

研究一种未引起足够重视的新的煤矿水害类型——覆岩离层水水害；通过采前覆岩结构类型、采动覆岩结构变异与水害特征分析，划分3种突水模式：高位覆岩破断动力突水、静水压突水与周期性来压突水模式。采用岩层冲击倾向性测试、抗弯曲试验、封闭水体冲击水压力试验、岩板破断微震特征物理模拟、采动岩体冲击破坏效应数值模拟等实验和模拟方法，研究“高位覆岩破断动力突水”的过程机制。进行离层水渗压与采矿扰动卸荷作用下的三轴渗透试验、渗流-应力-损伤耦合的理论分析与数值计算，揭示离层“静水压突水”通道形成的灾变机制。开展离层“周期性来压突水”的流固耦合物理模型试验与数值模拟，分析开采扰动下老顶/亚关键层周期性破断诱发离层水突出的多场信息演变特征与规律，揭示突水的内在机理。项目提出覆岩离层水涌突模式的3种类型，界定其发生条件，揭示其灾变机制；对丰富我国煤矿水害防治理论和技术、指导坚硬顶板矿区和深部开采水害防治实践具有重要意义。

随着煤矿开采深度增大，特殊条件开采增多等原因，覆岩离层水害频发，成为矿井安全生产的严重隐患。项目重点考虑离层水不同突水模式的发生条件与机理，主要内容、结果和关键数据如下：.1）获得了天然情况下覆岩结构组合模型，构建了采动影响下煤层-导水裂隙带-可积水离层带-高位坚硬覆岩的空间赋存模型。.2）利用三轴伺服试验系统，进行了离层水上覆岩层（淮北火成岩和崔木矿洛河组砂岩）的冲击倾向性测试，综合评价火成岩、砂岩分别具有中等-强烈、弱冲击倾向性。这也正成为了“高位坚硬覆岩破断突水”与“周期性来压突水”两种模式区别的主要原因之一。.3）以淮北杨柳矿101414工作面为原型，进行了火成岩封闭水体冲击水压力试验，以及火成岩破断瞬间对煤系地层冲击破坏效应UDEC数值模拟，其冲击荷载波形特征来自于模拟火成岩岩梁破断瞬间的微震试验结果。从实验与数值模拟角度共同证实了“高位坚硬覆岩破断突水”模式具有明显的冲击效应。.4）以济二矿11305工作面为原型，推导建立了离层水“静水压突水”的力学判据，并进行了工作面离层发育的离散元数值模拟与电法监测。共同揭示了静水压突水机理：在采矿扰动卸荷与离层水压力共同作用下，导水裂隙带上方先期形成的离层水被挤压涌入导水裂隙带内，形成离层水突出。.5）以崔木矿21302工作面为原型，进行了工作面离层发育的3DEC数值模拟、物理模型试验及其光纤监测，结合工作面内G3钻孔的水位监测记录，共同分析确定了可积水离层发育位置，揭示其突水机理：随着工作面不断推进，离层逐渐增大，至上覆洛河组岩层发生破断，离层封闭，离层水突出，后续离层空间再次重新发育，周期性持续此过程。.6）提出离层水3种突水模式的科学内涵，总结离层突水的直接原因与区分标准。.研究结果在离层水害的突水模式、发生条件、突水机理等方面的研究具有一定的新意；对指导坚硬顶板矿区和深部开采离层水害防治实践具有重要意义。.