诱导下岩体断裂冒落时空演化

As about 30%～60% of energy consumption in large metal mines is related to ore breaking,induced caving technique is an effect way to reduce mining energy consumption and improve the mining efficiency.The theoretical research of induced caving is behind the production practice at present,therefore rock masses fracture caving mechanism and predictive control method urgently need to be studied to enlarge application range. The paper put forward the caving concept to better reveal the dynamic process of rock mass caving, in the cavability basis to consider the space access conditions of fracture expansion and shear dilatancy, the regulation mechanism of disturbance stress, and the control action of free pressure arch structure changes. According to the property of the research content and the project that applicant undertaken. We use the advanced technology of RG camera, IMS microseismic monitor and CMS cavity scanning, combined the measured data of image analysis with numerical simulation, research the process of main crack generated upper cover rock, tensile fracture, extended to the space-time evolution of the caving rule with working face advances at the same time. The measure content which mining stress distribution and experimental research of collapsing granular media function in situ, reveal the mechanism of fracture and collapse. Finally, establish the representation of rock mass collapsing, the methods of rock mass classification, the mining stress control method and the space-time forecast and control of rock mass caving method, as theoretical foundation and basis to support the induction engineering and improvement of mining design.

大型金属矿山采矿能耗的30%～60%消耗于落矿，诱导矿岩自然冒落是地下采矿降耗增效的有效途径。目前诱导冒落的理论研究落后于生产实践，为提高诱导效率扩大应用范围，需要深入研究诱导冒落机理。基于诱导冒落动态过程，提出可冒性概念，研究岩体剪涨扩容空间、采场结构、采动应力调控与裂隙扩张的相互作用，以及免压拱对冒落的控制作用，建立简化力学模型，描述诱导冒落的主要过程，进行定量的定性分析裂隙扩张、岩体分离的机制。利用钻孔摄像、微震监测与空区扫描技术进行现场监测，获取岩体原生与采动裂隙结构的统计信息，将实测数据图像分析与数值模拟有机结合，并借助脆性相似材料模拟实验，研究回采工作面推进过程中上覆岩体主裂隙生成、张裂、扩展至冒落的时空演化规律，揭示岩体断裂冒落机理，结合诱导冒落法工艺研究，建立岩体可冒性表征与分级方法、采动应力调控方法、以及岩体冒落时空预测与控制方法，为诱导工程设计与采矿方法改进提供理论基础与依据。

诱导工程的扩容空间和卸压扰动，先使岩体原有裂隙扩张形成裂纹，裂纹按两者的获取优势扩张与贯通生成裂缝。裂缝进一步扩张后，裂缝之间“岩桥”碎裂贯通，逐条生成断裂线（断裂曲面）。断裂体两端由卸压-增压交界带支撑，支撑体不断破裂弱化引起断裂体错动，错动体两端被剪断冒落。.建立了临界冒落跨度计算式与冒落高度估算式，并用于排山楼金矿采空区治理。前者计算值与实际误差4.10%，后者估算值与钻孔实测误差9.73%，验证了两式的可用性。基于诱导冒落高度的定量计算，提出一种诱导冒落嗣后充填采矿方法，并用于中关铁矿，预计可大幅度提高采场生产能力、改善生产安全条件与降低生产成本。提出拱型大冒落模型，更好解释了大冒落时的大地晃动，以及地表由近及远形成塌陷坑、断裂线、裂缝、裂纹等现象，并为冒落进程钻孔监测提供指导。建立了临界大冒落跨度计算式，提出大冒落危害适时预防方法。用于小汪沟铁矿，将常规的十余年预防期缩短到43天，显著提高了预护可靠性。.模拟得出矿体埋藏深度对矿岩冒落影响较小；冒落高度与体积随侧压力系数的增加先减小后保持稳定；拉底长宽比越大，冒落高度与体积越小；冒落高度随拉底跨度的增加先增大后保持稳定，高跨比逐渐减小。提出表征可冒性的定量指标，既包含常用可冒性主要评价指标，也包含诱导冒落特有动态指标，并提出可冒性模糊综合评判方法。.提出地表塌陷坑是采空区冒透地表时（碎胀后）剩余体积上移的观点，建立了塌陷范围的理论方程。应用于西钢灯塔矿业公司小汪沟铁矿，计算圈定的塌陷范围与实际塌陷范围的误差小于5%，证明理论计算公式符合实际。用新理论方程计算圈定的塌陷范围，比传统方法圈定的塌陷范围小了近十倍，极大减小了塌陷区土地占用时空。基于岩体冒落过程的扩容空间需求与散体侧压力支撑作用，提出临界散体柱支撑理论，用于小汪沟铁矿，采用废石充填塌陷区控制采动岩移范围，实现了塌陷角内倾76°，错动范围比设计减小48.5%。