大规模开采的矿山存在复杂的诱导地震活动,在高应力硬岩条件下具有产生区域性危险地震和岩爆灾害的可能性,震源的地震视应力和变形参数是地震机制和地震活动性预测研究的重要参数,对此开展研究具有重要意义。针对冬瓜山铜矿深井开采诱导地震活动,对地震视应力和位移在矿区开采过程中的时空特征开展研究,发现地震活动具有区域性分布特征,其时空分布与开采活动及矿区矿柱分布具有较强的对应关系。以此为依据,结合矿区地质构造和地应力状态,研究该矿区区域性地震机制,指出可以利用天然地震复杂震源的凹凸体理论来解释该矿区区域性地震成核机制,从而提出该矿区区域性危险性地震成核概念模型,并针对该矿地震活动的特征讨论识别成核区的方法。针对该矿区域性岩体破坏实例,分析地震视应力和变形参数时间序列特征,讨论潜在区域性地震成核区的地震活动危险性和岩体破坏性态的评价与预测。研究结果在工程实践中得到实际应用。
In the mine under large-scale mining,the complex seismicity induced by extensively mining are familiar;and under the conditions of high stress and hard rock,the areal hazardous seismicity and rockbursts are probable.The seismic apparent stress and deformation are important hypocenter parameters to study the seismic mechanism and prediction.According to the Dongguashan Copper Mine,the characteristics of seismic apparent stress and displacement in the mining process are investigated;and we find that the seismicity shows the areal distribution characteristics which have greatly corresponding relation to the mining activity and distribution of pillars in this mining area.Based on the results,combining with the geological structure and in-situ stress,the areal seismic mechanism in this mining area is studied.It is pointed out that the seismic nucleation mechanism can be explained with the knaggy theory of complex hypocenters of natural earthquakes;and a conceptual model of seismic nucleation in the mine is proposed.Simultaneously,a method to identify the location of potential hazardous seismic areas is discussed in accordance with the seismicity characteristics.Aiming at the areal rock failures,the characteristics of time series of apparent stress and apparent volume are analyzed;and the prediction and assessment of rock failure behavior and seismic risk in the potential seismic nucleation zone are discussed.The research result is applied to the project.