基于微震活动性参数研究在岩体稳定性预报中的重要性,探讨b值、能量指数EI、施密特数SCS、累积视体积∑VA等微震参数在顶板冒落前后的变化,提出“能量指数与累积视体积之比(EEI)”以及“施密特数与累积视体积之比(ESCS)”的概念,并将其作为岩体稳定性预测的参数。结合前人对b值与事件数在岩体稳定性预测中的研究,以这3组参数建立微震监测预报的一般模式,应用到用沙坝矿岩体稳定性预测。结果表明:b值在顶板冒落前先增大后减小的趋势具有危险预警的功能;能量指数、施密特数急剧下降以及累积视体积增加,表征了岩体内累积应变能的突然释放,预示围岩稳定性的劣化。这种微震监测预报手段综合确定的预警期更适合矿山,并留有一定的响应时间以规避风险。
The studying on parameters of microseismic activity play an important role in rock mass stability prediction. The change pre- and post Roof Caving of microseismic activity parameters including b value, Energy Index, Schmidt number and cumulative apparent volume were discussed in this article. The author puts forward the concept of "the ratio of energy index and cumulative apparent volume(EEl)" and "the ratio of Schmidt number and cumulative apparent volume(Escs)" . The EEI and Escs could be used as the parameters of rock mass stability prediction. Based on the research of b value and number of events, the general pattern of microseismic monitor forecasting were built. The pattern were used in rock mass stability prediction in Yongshaba mine, and the results showed that: the b value had the function of risk warning because it first increase then decrease pre- and post roof caving. The decrease of energy index and Schmidt number with the increase of cumulative apparent volume meant sudden release of accumulated strain energy in rock mass. The phenomenon indicated deterioration of rock stability. The early warning period that comprehensive determined by this microseismic monitoring forecasting method was more suitable for mine, and reserved response time for workers to avoid risk.