坚硬顶板褶皱复合型冲击矿压前兆信息识别及监测预警指标研究

Stress near fold structure region in coal mine is complex, and roof strata above these areas are normally hard. Due to high stress of fold structure and strong dynamic load induced by hard roof strata, rock burst occurs frequently during the coal seam mining. In view of this situation, this project is centered on the inducing process of roof-and-fold induced rock burst, and the precursory information identification and the comprehensive monitoring and early warning method will be systematically studied. Finite element and discrete element methods will be used to analyze the influence law of fold morphology, coal and rock properties, etc. on mining stress evolution and overburden breakage. Based on true tri-axial loading and unloading tests under coupled static and dynamic loads and physical simulation tests under static and dynamic combined loads, the impact of fold structure on the tendency of coal-rock mass and the response law of multi physical fields during coal seam excavation will be investigated. Combining with numerical simulation, indoor experiments and engineering monitoring, the multi-scale and multi-source precursory information of roof-and-fold induced rock burst, its fusion characteristics and evolution law will be studied. Main control factors will be screened and normalized warning model of mechanics will be established. The multi-source and multi-level monitoring index system will be constructed by revealing the root cause of roof-and-fold induced rock burst. Based on the index weight quantization and normalization processing, by using the comprehensive anomaly index and R score methods, the comprehensive early warning model and the discriminant criterion will be proposed, and the early warning software platform will be developed. The outcome of this project can provide references to the control of roof-and-fold induced rock burst.

煤矿褶皱构造区应力复杂，加之赋存坚硬顶板岩层，由于褶皱高应力与顶板强动载的复合作用，煤层开采时冲击矿压动力灾害频繁发生。针对这一现状，项目以顶板褶曲复合型冲击孕育过程为核心，系统开展其前兆信息识别与监测预警方法研究。模拟分析研究褶皱形态、煤岩属性等对褶皱煤层开采应力演化与覆岩破断的影响规律；基于真三轴动静加卸载、动静加载物理模拟试验，研究褶皱构造对煤岩冲击倾向性的影响规律，以及煤层开挖冲击破裂过程的多物理场响应规律；结合细观模拟、室内实验与工程原位监测，研究多尺度下顶板褶皱复合型冲击灾变过程多源前兆信息及其融合特征、演变规律，筛选主控因素，建立归一化预警力学模型；以揭示冲击灾变前兆信息为中心，构建多源多级监测指标体系；基于综合异常指数、R值评分的指标权重量化与归一化处理，提出综合预警模型与判别准则，开发预警软件。通过项目研究，为控制顶板褶皱复合型冲击矿压提供技术支撑。

煤矿冲击矿压是煤岩动力灾害之一，已成为制约煤矿安全生产的关键因素。我国诸多地区存在“褶皱发育、顶板坚硬”等特殊地质条件，导致冲击矿压频发。为此项目以顶板褶曲复合型冲击孕育过程为核心，综合采用理论分析、数值模拟、相似模拟、神经网络、工程实践、软件开发等手段系统开展其前兆信息识别与监测预警方法研究具有重要的理论意义及实用价值。.提出了褶皱顶板复合型冲击矿压孕育过程与灾变机理，揭示了褶皱区顶板型冲击机理，向斜轴、背斜及翼部巷道冲击类型分别为“高静载、弱扰动”、“低静载、强扰动”及“动静平衡”型。探究了工作面回采过程中褶皱区煤岩在坚硬顶板影响下的冲击孕育规律，分析了工作面向斜、背斜轴部俯采、仰采及翼部仰采时应力、能量、塑性区和震动事件分布演化特征。.识别了顶板褶皱复合型冲击矿压的多尺度多源前兆信息，首先提出了冲击矿压“三场”监测原理及监测预警指标，分析了数值模型、实验室试验及现场观测冲击时的“三场”前兆信息，筛选得到监测预警指标。用于应力场预警指标为震动波层析成像；用于能量场预警指标为冲击变形能；用于震动场监测的b值、活动度等4个预警效果较好指标及断层总面积、震中集中度等4个预警效果中等指标，揭示了冲击孕育灾变全过程的可测信息特征及变化规律。.建立了顶板褶皱复合型冲击矿压的多源信息综合预警指标与判别准则，基于神经网络模型得到各指标权重，模型预警准确率为87%，利用熵权法计算各场指标综合权重；建立了冲击矿压多参量综合监测预警模型，提出了顶板褶皱复合型冲击矿压的归一化无量纲综合预警方法及其危险分级判别准则。.研发了顶板褶皱复合型冲击矿压的多源信息时空强监测预警平台，基于研究得到的预警指标及模型设计平台架构，平台具备自动采集数据、自动化分析功能，同时可根据分析结果完成区域预测，提出风险点及风险来源。