微震法岩爆监测及其在荒沟电站地下厂房区的应用分析

Rockburst Monitoring by Microseismic Method and Its Application in Underground Powerhouse of Huanggou Hydropower Station

近年来,深部地下洞室开挖诱发的岩爆地质灾害问题日益突出,以岩体微破裂定位为特色的微震监测技术被广泛应用于地下工程的岩爆监测与预警。以荒沟抽水蓄能电站地下厂房区为背景,针对开挖过程中局部围岩出现的轻微岩爆现象,构建微震监测系统进行岩爆监测预警,并对监测期前两个月的微震活动进行了分析。结果表明:微震系统可以有效地捕捉高频的爆破事件和低频的微震事件;微震事件活动频度与现场爆破开挖施工强度呈正相关;厂房上游侧拱肩和下层排水廊道与厂房安装间交汇部为岩爆潜在风险区。研究成果可为地下洞室的安全施工和稳定性评价提供技术支撑。

In recent years,rockburst induced by excavation of deep underground caverns has become increasingly prominent.Microseismic monitoring technology characterized by micro-fracture location of rock mass has been broadly utilized in rockburst monitoring and early warning of underground engineering.In this paper,a microseismic monitoring system for rockburst monitoring and early warning for the slight rockburst of local surrounding rock during excavation was established and adopted to analyze the microseismic activity in the first two months of the monitoring period.The underground powerhouse area of Huanggou Pumped Storage Power Station was taken as a case study.Results suggest that the frequency of microseismic events is positively correlated with the intensity of blasting excavation.The upstream side arch shoulder and the intersection between lower drainage corridor and workshop installation room are the potential risk areas of rockburst.The research finding offers technical support for the safe construction and stability evaluation of underground caverns.