含瓦斯煤岩冲击破坏前兆及多信息融合预警研究

发布时间：2018-02-14 18:37

本文关键词： 瓦斯煤层冲击失稳前兆信息融合预警　出处：《中国矿业大学》2013年博士论文　论文类型：学位论文

【摘要】：随着煤矿开采深度的增加和开采强度加大，高应力、高瓦斯使得冲击地压的发生日趋严重和复杂。针对含瓦斯煤层，考虑瓦斯对煤层冲击地压的作用机制，将瓦斯与应力、声电、微震等指标相结合实现有效融合预警，对于揭示含瓦斯煤层冲击地压机理、完善矿井冲击地压预防技术具有重要的理论和现实意义。基于此，，本文建立了含瓦斯煤岩受载破坏前兆信息三轴实验系统，实现了含瓦斯煤受载破坏过程中的电磁辐射、声发射、瓦斯等参数的实时同步测试分析；分析了含瓦斯煤层冲击地压演化过程的瓦斯涌出规律，研究了含瓦斯煤层冲击地压过程的电磁辐射、微震（声发射）、瓦斯、采动应力的前兆信息特征；建立了基于D-S证据理论的含瓦斯煤层冲击多前兆信息融合预警模型和方法，并进行了现场验证及应用。主要取得了以下研究成果：（1）建立了含瓦斯煤岩受载破坏前兆信息三轴实验系统，可实现不同围压、不同瓦斯压力条件下煤岩受载破坏声电、瓦斯、应力、应变等参数的实时同步测试；实验研究了不同围压条件下煤岩破坏的力学特征和声电、瓦斯等参数的变化规律。研究结果表明：煤样破坏载荷随着瓦斯压力的增大而减小，随着围压升高而增大；声电信号随着载荷的增大而不断增多，信号强度不断增大；试样加载至峰值破坏时，瓦斯压力和排放量出现突然增大的现象。（2）基于声电特性参数建立了考虑残余强度的煤岩损伤演化模型，通过模型研究了声电信号变化规律与煤岩受载破坏程度的对应关系。（3）建立了考虑瓦斯吸附膨胀的煤岩渗透-损伤耦合演化模型，依此揭示了含瓦斯煤层冲击失稳过程瓦斯涌出异常的内在机制，并提出瓦斯可作为含瓦斯煤层冲击失稳的一种预警指标；结合含瓦斯煤层冲击地压的瓦斯涌出、电磁辐射、微震（声发射）和采动应力等监测数据，揭示了煤矿含瓦斯煤层冲击失稳的前兆信息特征。（4）基于多种信号前兆响应规律建立了含瓦斯煤层冲击地压预警指标体系，确定了预警指标的临界值计算方法，提出了基于D-S证据理论的信息融合预警模型及方法，并进行了现场验证及应用，结果表明：随着冲击事件时间的临近，冲击危险程度呈现由无到中再到高的变化趋势，危险概率逐渐增大；冲击危险预警准确率较高，无漏报现象。
[Abstract]:With the increase of mining depth and mining intensity, high stress and high gas make the occurrence of impact ground pressure become more and more serious and complex. Considering the mechanism of gas acting on coal seam, gas and stress are considered. The combination of acoustics and microearthquakes to realize effective fusion and early warning is of great theoretical and practical significance for revealing the mechanism of rock burst in gas-bearing coal seam and for perfecting the prevention technology of mine impact ground pressure. In this paper, a triaxial experimental system of precursor information of loaded destruction of gas-bearing coal and rock is established, and the real-time synchronous measurement and analysis of electromagnetic radiation, acoustic emission, gas and other parameters in the process of loaded destruction of gas-bearing coal are realized. The characteristics of electromagnetic radiation, micro-earthquake (acoustic emission, gas, mining stress) in the evolution process of gas bearing coal seam are analyzed. Based on D-S evidence theory, the early warning model and method of multi-precursor information fusion in gas-bearing coal seam impact are established, and the field verification and application are carried out. The main research results are as follows:. 1) A triaxial experimental system of precursor information of coal and rock loading damage with gas is established, which can realize real-time synchronous measurement of acoustic, electrical, gas, stress and strain parameters of coal and rock under different confining pressure and different gas pressure. The mechanical characteristics of coal and rock failure under different confining pressure and the variation law of parameters such as acoustic electricity and gas are studied experimentally. The results show that the failure load of coal sample decreases with the increase of gas pressure and increases with the increase of confining pressure. With the increase of the load, the acoustic signal increases and the signal intensity increases, and the gas pressure and discharge increase suddenly when the sample is loaded to the peak value. (2) based on the parameters of acoustoelectric properties, the damage evolution model of coal and rock considering residual strength is established, and the relationship between the change of acoustic signal and the damage degree of coal and rock under load is studied by the model. (3) the coupling evolution model of permeability and damage of coal and rock considering gas adsorption and expansion is established, which reveals the inherent mechanism of abnormal gas emission in the process of gas bearing coal seam impact instability. It is suggested that gas can be used as an early warning index for impact instability of gas-bearing coal seams, and combined with monitoring data of gas emission, electromagnetic radiation, microseismic (acoustic emission) and mining stress, etc. The characteristics of precursor information of coal seam impact instability in coal mine are revealed. 4) based on the law of precursor response of various signals, the index system of pressure-pressure-early warning in gas-bearing coal seam is established, the calculation method of critical value of early-warning index is determined, and the information fusion early-warning model and method based on D-S evidence theory are put forward. The field verification and application show that with the approaching of the impact event time, the risk degree changes from no to middle to high, and the risk probability increases gradually, and the accuracy of early warning of impact danger is high, and there is no underreporting phenomenon.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TD712

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