深部巷道岩爆与声发射活动时空演化关系实验研究

With the increase of mining depth，the frequency and intensity of rock burst increase constantly. As a result, it becomes particularly important to study its inoculation and occurrence mechanism, and set up a corresponding early warning mechanism. According to the adjustment of deep mine roadway's excavation-unloading stress and the characteristics of nonlinear deformation damage, the biaxial experimental machine is used to simulate the roadway's strain rock burst of deep brittle rock. Through the simulated experiment of roadway's rock burst with dry and hydrous rock sample, the occurrence form of deep mining roadway's rock burst and the influence of the lithology ，stress, water, tunnel's size and so on are studied. In addition, the Bayesian Discriminant analysis method is utilized to establish the hierarchical evaluation model of rock burst's intensity prediction. Field emission scanning electron microscope and stereoscopic microscope were used to study the rules of deep roadway's crack initiation, extension and fracture, and analyze the characteristics of temporal-spatial evolution in gradual damage process of fissure's expansion, cut-through until broken under different influencing factors, in order to reveal the inoculation mechanism of brittle rock roadway's rock burst. Using the experimental data, with the method of theoretical analysis and numerical simulation, the power's forming process and occurrence conditions of rock burst are examined, and the occurrence mechanism of rock burst from the angle of the dynamics and energy is analyzed.Through the analysis of the temporal-spatial evolution relationship between rock burst of deep roadway and acoustic emission, infrared radiation, as well as the abnormal characteristics and rules, a joint early-warning monitoring method is formulated, which provides theoretical and technical basis for monitoring and early warning of rock burst.

随着矿井开采深度的增加，岩爆频率和烈度不断增加，研究深部岩爆孕育、发生机理，建立相应的预警机制显得尤为重要。根据矿山深部巷道开挖卸压应力调整和非线性变形破坏的特点，利用双轴实验机模拟深部脆性岩石巷道应变型岩爆。通过干燥和含水岩样的巷道岩爆模拟实验，研究深部开采条件下巷道岩爆的发生形式以及岩性、应力、水、巷道尺寸等因素影响，应用贝叶斯判别分析法建立岩爆烈度分级预测的评价模型。利用场发射扫描电镜和体式显微镜研究深部巷道矿岩裂纹开裂、延伸和断裂规律，分析不同影响因素下岩石裂隙的扩展、贯通直至破裂成灾的渐进损伤过程中AE时空演化特征，揭示脆性岩石巷道岩爆孕育机理。利用实验数据，采用理论分析和数值模拟的方式，从动力学和能量角度研究岩爆动力源形成过程和发生条件，分析岩爆发生机理。分析深部巷道岩爆与声发射、红外时空演化关系以及异常特征和规律，建立联合监测预警方法，为岩爆监测预警提供理论与技术基础。

本项目以深部巷道岩爆为研究对象，采用室内试验、数值模拟和理论分析相结合的研究方法，将岩爆破坏特征、孕育机制与监测预警有机结合，开展了系统性实验研究，达到了预期目标。研究成果如下：（1）设计了巷道岩爆“岩石+相似材料”组合实验模型，采用“开孔后充填+开挖+应力调整”的实验方法，实现了岩爆实验中开挖卸荷与应力调整过程的有机统一，弥补了以往岩爆实验“先开孔，后加载”无卸荷效应的不足。通过对比分析，岩爆模拟实验结果与实际工程巷道岩爆发生过程一致，达到了岩爆模拟的实际效果，得到了不同因素对岩爆过程的影响规律，可为现场复杂环境下岩爆分析提供依据。（2）首次通过CT技术获得了巷道岩爆实验中岩爆坑的全景可视化模型，将岩爆破坏研究从定性提升到定量研究的轨道上。实验中观测到“V”型与“平底锅”状两种岩爆坑形态，揭示了岩爆后洞壁破坏形态在空间分布上具有显著的二元性，并提出了“V型岩爆坑窄而深、平底锅状岩爆坑宽而浅”的基本认识，在此基础上，根据爆坑形态将岩爆细分为“V”型与“平底锅”状两种类型，结合声发射特征和微观断口分析，获得了两种类型岩爆孕育机制上的异同点，丰富和完善了目前对岩爆孕育机制的认识。（3）基于声发射监测，系统分析了巷道岩爆过程能量变化特征，得到了岩爆过程声发射能率“多点陡增”状、累计能量“台阶”状上升的演化规律，以及曲线陡增点、台阶等特征与岩爆过程现象的对应关系，并从能量的角度揭示了岩爆过程能量积聚-释放响应规律。采用数值模拟的方法，获得了巷道开挖后深处围岩高能量向巷道壁面空间运移规律，揭示了岩爆动力源的形成过程，为岩爆发生风险评估、巷道围岩支护设计提供依据。（4）将声发射信号时间、主频和幅值作为一个有机整体，从时、频、幅三个维度综合分析，发现临近岩爆低频高幅值信号数量和密集性呈现双增长特征，根据实验确定了低频高幅值信号的优选依据，提出了现场岩爆应重视低频高幅值（能量）信号的监测原则，进一步建立了基于低频高幅值信号时间密集度的岩爆声发射时序预警方法。基于岩爆红外热像分析，岩爆发生部位温度场出现高、低温分异现象，选取温度场分异速率作为预警指标，分别构建了岩爆红外辐射空间与时间预警方法。以此，形成了基于时空架构的巷道岩爆“声发射-红外辐射”联合监测预警技术，实现了岩爆灾害的时空综合预警。研究成果可为矿山巷道岩爆灾害孕育机制分析、监测、预警提供关键的基础理论支撑和技术支持。