以锦屏二级水电站岩爆高发洞段作为研究对象,采用微震监测技术作为岩爆监测预警手段。通过对比现场实际情况和微震监测结果,揭示出微震的时空演化与岩爆之间的关系;通过岩体损伤过程特征提取对应的微震监测事件,总结出微震事件密度云图、微震事件震级与频度的关系、微震事件震级、能量集中度等微震监测指标规律,并以地震学中的3S原理作为岩爆判断基础,提出4个岩爆判据。现场应用结果表明:在深埋岩体隧洞中,岩爆的时间、空间、强度等分布存在较明显的规律性,微震活动对岩爆事件普遍具有时间优先性和空间一致性,应用该岩爆判据能够达到岩爆危险区域的精确预测,为隧洞的岩爆预测和微震监测预警提供依据。
The rock burst-prone tunnel section in Jinping II hydropower station was studied using micro-seismic monitoring technology as a means of monitoring and early warning of rock burst. The spatial and temporal variations of mirco-seismic events and rock burst were revealed by comparing the actual conditions and monitored micro-seismic results. The relationships among the magnitude,frequency and energy for micro-seismic events contour were revealed through the extraction of micro-seismic monitoring events by the corresponding characteristics of rock damage process. The four criterions of rock burst were presented based on 3S principle in seismology to determine rock burst. The in-situ results of the study showed that the regularity of the temporal,spatial and intensity distribution of rock burst in deep tunnels existed. Micro-seismic activities always occurred ahead of rock burst,while the locations of them coincided with rock burst. The criterion of rock burst can be used to make accurate early-warning,and provide evidence for rock burst forcasting and micro-seismic monitoring early-warning.