Microseismic monitoring, analysis and early warning of rockburst

Abstract

Rockburst hazard is one of the most outstanding problems in deep rock mechanics, which has become the bottleneck for deep underground engineering in China. Rockburst occurs with some evident precursors, however, the rockburst mechanism is not clearly revealed. The acoustic emissions (microcracks) occur before the failure of rockmaterial, and rockburst is the sudden failure of rock mass caused by the development of microcracks. Therefore, it is effective to study the microcrack precursors for the surrounding rock of deep-buried tunnels by the microseismic monitoring system, and to warn of the rockburst. A method for monitoring and warning of rockburst in deep underground engineering is proposed based on the study of rockburst mechanism and in situ experience for many years. Main points of the proposed method are numerical simulation based on the monitoring, warning of rockburst based on the numerical simulation, and control of rockburst based on the warning. The proposed method was applied and improved successively in the deep-buried tunnels of the Jinping II Hydropower Station and the Hanjiang-to-Weihe River Diversion Project, which may prevent the occurrence of rockburst or decrease the incidence of rockburst. The proposed method is fast, accurate and intelligent by integrating the microseismic monitoring, artificial intelligence, big data and large-scale numerical analysis, and may be promoted to other deep underground engineering.

Keywords

• deep-buried tunnel
• rockburst
• precursor
• monitoring
• early warning