SCALING LAWS AND THEIR IMPLICATIONS FOR RE-ENTRY PROTOCOL DEVELOPMENT
The statistical properties of empirical scaling relations, such as the modified Omoris law n(t)=K(c+t)-p for the temporal decay of aftershocks following a main event and Baths law Δm for the magnitude of the largest aftershock are examined for mining-induced aftershock sequences in a number of mines in Ontario, Canada. We focus our attention on significant statistical correlations of seismic parameters for re-entry protocol development after blasts and large events. The Omoris law parameters along with their error assessment are estimated using the maximum likelihood method and considering only the time interval that satisfy power-law behaviour (c-0). The sites analysed presented normally distributed p values, ranging from 0.4 to 1.6. The parameter A can be satisfactorily expressed as K-κN1 hour, where κ is well represented by a log-normally distributed variable with parameters μ and σ. and N1 hour is the measured number of events occurring during the first hour after the main event. We found that μ and σ are in a well constrained range with mean values of 0.334±0.060 and 0.1 46±0.043, respectively. Using Monte Carlo simulation, isoprobability curves arc derived for estimating a re-entry time after a main event. Baths law was evaluated for seismic moment magnitude. The results are more scattered due to the limitations of microseismic monitoring systems to appropriately quantify large magnitude events. However, normally distributed values of Δm were found at the three sites, with a mean value of 1.2S±0.31. Mining-induced aftershock sequences present similar scaling properties to earthquakes. The practical implications of these statistics for re-entry protocol development one hour after a main event are: (1) a probabilistic re-entry time can be estimated; (2) the most probable largest aftershock for a specific time window can be estimated.
JAVIER-A.VALLEJOS STEPHEN-D.MCKINNON
Department of Mining Engineering, Queens University Kingston ON K7L3N6, Canada
国际会议
The 7th International Symposium on Rockburst and Seismicity in Mines(2009年第七届国际岩爆与微振动性学术研讨会)
大连
英文
1057-1066
2009-08-21（万方平台首次上网日期，不代表论文的发表时间）