微震波在受载岩体内传播的能量耗散机制与衰减特性研究

Microseismic monitoring technique plays an increasingly important role in the prediction, evaluation and control of geological dynamic disasters in underground mines. However, how to effectively apply microseismic data into the prediction of mine dynamic disasters is a hard research interest which has still been explored. In this research project, microseismicity in heavy rock roof of working face is taken as the research object. Based upon multi-dimensional models and data obtained from the experiments of microseismic wave transmission in loading rock specimen, medium-transmitting model and dynamical equation of microseismic wave are established. Quantitative relation between propagation distance and residual wave energy is explored. Energy dissipation mechanism and fundamental attenuation characteristics of microseismic wave in rock medium under high stress are revealed. Characteristic impacts of rock structure and stress distribution on wave energy dissipation are thoroughly studied, and the major factor is expounded. Coupling relationship responded by the triaxial parameters composed of energy dissipation, rock structure and loading stress is revealed. Attenuation inversion method of microseismic wave energy, represented by energy dissipation coefficient and medium quality factor, is developed. Regional prediction method for mine dynamic disasters directed by energy dissipation and attenuation characteristics of microseismic wave is put forward. Achievements of this program can further promote the improvement of theoretical system, and provide a new research thought for the prediction of mine dynamic disasters, which have an important practical significance for protecting safe scientific mining of deep coal resources.

微震监测技术在矿井地质动力灾害的预测、评价与控制方面发挥着日益重要的作用。然而，微震数据如何有效地应用于矿井动力灾害的预测预报是一直在探究的难题。本项目以工作面顶板内的微震活动性为研究对象，基于微震波透射受载岩体的多维度实验模型和数据，建立微震波的传播介质模型和动力学方程，分析传播距离与残余波能的量化关系，揭示微震波在受载岩体介质内传播的能量耗散机制与基础衰减特性；深入研究岩体构造特性与应力分布特性对波能耗散特性的影响并阐释其关键影响因素，揭示波能耗散、岩体构造、应力载荷三参量之间的耦合响应关系；发展以能量耗散系数和介质品质因子为表征的微震波能量衰减反演方法，提出以微震波的能量耗散衰减特性为判据的动力灾害区域性预测方法。研究成果可进一步促进矿井动力灾害预测预报理论体系的完善并提供新的探索思路，对保障我国深部煤炭资源的安全科学开采具有重要的实际意义。

当前，以冲击地压、煤与瓦斯突出、突水为代表的诱发性矿井地质动力灾害已成为威胁我国煤炭工业安全生产的关键问题。矿井动力灾害事故是高地应力场空间集聚运移与煤岩构造弹塑形变失稳破坏耦合作用的结果。为了实现对矿井地质动力灾害较高可靠性的预测预警，本研究以采掘生产活动影响下工作面围岩内频繁发生的微震现象为研究对象，完成了大量实验室岩石样品声发射测试、计算机正反演模拟、工程现场微震连续监测等试验分析研究。基于微震波透射受载岩体的多维多场实验模型和数据，建立了微震波的传播介质模型和动力学方程，分析了传播距离与残余波能的量化关系，对地应力场作用下岩体构造内的微震波传播时的衰减特性进行了基础性研究，揭示了微震波在受载岩体介质内传播的能量耗散机制；深入探索了岩体构造特性与应力分布特性对波能耗散衰减特性的影响并阐释其关键影响因素，揭示了波能耗散、岩体构造、应力载荷三参量之间的耦合响应关系，以此挖掘微震波内在的物理力学特征信息与灾害前兆信息的紧密关联性，提高了对有效微震事件的分析解释能力，发展了以能量耗散系数和介质品质因子为表征的微震波能量衰减反演方法，提出了以微震波的能量耗散衰减特性为判据的动力灾害区域性预测方法；形成了基于DDA算法的高噪信号精细降噪解析技术、基于P/X奇异时至特性的震源非线性精确定位技术、基于震动波场耗散衰减特性的源能矢量聚焦反演技术、基于微震大数据统计模型的灾害危险性定量评价技术等创新技术，在微震、声发射等被动震源的聚焦定位、能量核定、波速求解、波场反演等多个方面取得了创新性成果。针对微震数据如何有效地应用于矿井动力灾害预测预报方面的可行性，完成了既定的研究目标，研究成果从区域性预测的角度进一步促进了矿井动力灾害预测预报理论体系的完善并提供新的探索思路。