裂隙矿岩顶板稳定性分级及崩落法回采失稳机制研究

Because were natural cut by structural surface and influenced by engineering excavation disturbance, the engineering roof easily happens roof fall and sudden scale collapse accident, serious threat to the enterprise safety in production, especially for mining enterprises, thus it is of great significance to carry out the researches of fractured rocks roof stability classification and instability mechanism of caving mining method. This project conducts the researches of the deconstruction method and the authenticity analysis of fractured rock by using the key block theory and general block theory, based on engineering geological survey; A new classification methods and standards of the fractured rock roof stability are researched from three-dimensional perspective through introducing the block theory of fractured rock mass; Through introducing the rock structure deconstruction results into three-dimensional numerical calculation model, the instability law of fractured rock roof is analyzed in order to reveal the instability mechanism of rock roof; Safety control method of roof block surrounding rock is researched based on the mining influence; Research results is benefit to understand the stability state and instability mechanism of engineering roof from microcosmic aspect, and conducive to promote the intrinsically safe prevention of engineering geological disaster.

受结构面自然切割及工程开挖扰动影响，工程岩体顶板极易发生冒顶、片帮及突然性大规模垮塌事故，严重威胁企业安全生产，特别对矿山企业影响更甚。因此，开展裂隙矿岩顶板稳定性分级及崩落法回采失稳机制研究具有重要意义。本项目利用关键块体理论与一般块体理论，在工程地质调查的基础上，开展裂隙岩体结构解构方法研究及真实性分析；引入裂隙岩体块体化程度理论，从三维角度研究裂隙岩体顶板稳定性的分级新方法与标准；将岩体结构解构结果导入三维数值计算模型，分析裂隙岩体顶板崩落法回采失稳规律，揭示顶板失稳机制；基于采动影响，研究出顶板围岩危险块体安全控制方法。研究成果有助于从微观上认识工程岩体顶板稳定性状态及失稳机制，有利于促进工程地质灾害的本质安全化预防。

受结构面自然切割及工程开挖扰动影响，工程岩体顶板极易发生冒顶、片帮及突然性大规模垮塌等事故，严重威胁企业安全生产，特别对矿山企业影响更甚。因此，开展裂隙矿岩顶板稳定性分级及崩落法回采失稳机制研究具有重要意义。在铜坑矿 92 号矿体裂隙矿岩崩落法开采区域选取了4个具有代表性的区域作为试验区；以块体理论为基础，结合崩落法回采工艺，通过对崩落法回采过程中巷道顶板危险结构体的解构，形成了一种裂隙矿岩崩落法回采巷道顶板的解构法；引入裂隙岩体块体化程度分级理论，以块体化程度代替常规标准中表征岩体完整性的岩体质量RQD 值和节理间距两项子指标，开展了基于该理论的裂隙岩体巷道顶板稳定性分级研究，而创新形成了一种特别适用于裂隙岩体工程顶板稳定性分级的 BT 分级方法；同时从三维空间上运用块体化程度指标刻化了顶板围岩的完整性，建立了以块体化程度、单轴抗压强度、节理条件和地下水条件为指标的评价体系；基于裂隙岩体崩落法开采巷道顶板结构解构，构建了3DEC数值模型，对崩落法回采过程进了行动态模拟，分析了顶板结构体从开始移动到最终失稳的全过程，确立了结构体运动形式，并对大量结构体运动形式进行了分析，确立了巷道顶板危险结构体的失稳机制；通过分析巷道围岩不同失稳模式采取相应的针对性支护措施，研究出裂隙岩体巷道顶板分区支护方法，并将分区支护方案数值模拟结果和按岩体质量分级支护方案数值模拟结果进行对比，结果表明：分区支护可起到很好的支护效果。研究成果有助于从微观上认识工程岩体顶板稳定性状态及失稳机制，有利于促进工程地质灾害的本质安全化预防。