Lasocki, Stanislaw (2009) Probabilistic seismic hazard analysis for mining-induced seismicity. In: RaSiM 7(2009): Controlling Seismic Hazard and Sustainable Development of Deep Mines, C.A. Rinton Press, New York/New Jersey, pp. 59-72. ISBN 978-1-58949-058-1
Full text not available from this repository.Abstract
Many examples have shown that the seismic activity accompanying underground mining works can be hazardous both to underground staff and mining installations, as well as to ground structures. Due to their shallow focal depth, smaller as compared to natural earthquakes mining seismic events can give rise to damaging ground motion. The probabilistic seismic hazard analysis (PSHA) is a standard tool to estimate expected seismic impacts of earthquakes. Mining-induced seismicity, however, significantly differs from the earthquake process. First, the seismic activity in mines is predominantly controlled by time-varying mining works, therefore the active zones are, by their nature, transient. Moreover, even during their lifetime, the activity of these zones is not stationary but changes considerable. Second, due to the heterogeneity of the rockmass fracturing process in mines, the magnitude distribution of seismic events induced by exploitation is complex and its modeling based on the Gutenberg-Richter's relation usually leads to large systematic errors of hazard parameters. Third, the ground motion resulting from weak mining seismic sources is strongly influenced by local path and site conditions and the attenuation relations from one region are poorly applicable to the other region. All these differences cause that the standard PSHA methods cannot be readily applied to mining seismic problems. A probabilistic approach to the seismic hazard assessment, radically adjusted to mining seismicity, is presented in this paper. In these modified procedures, locations and times of activity of the seismic zones that will be active in the future are deduced from programs of mining operations. From all mine areas of past seismicity experts select those whose mining and geologic conditions are expected to be similar to the conditions of the zones of future activity. Probabilistic characteristics of the seismic activity of these areas and their changes in time give rise to the alternative time dependent models of the future zone seismic activity. The model-free approach with the non-parametric kernel estimator of magnitude density is applied to represent the source size distribution. This approach ensures cumulative distribution function and related parameters estimate which are free from epistemic uncertainty and have of tolerable aleatory variability regardless the actual complexity of the underlying magnitude distribution. The attenuation relations, used to convert the probabilistic characteristics of the future seismic source into the probabilistic haracteristics of the future ground motion, are identified from multiple acceleration signals recorded in the region under study and therefore are linked to local conditions. Estimation of the relative local amplification factors and the use of spectral ordinates in addition to the peak motion amplitudes reduces uncertainty of this step of the hazard analysis. The alternative possibilities of the seismic process development in the future zones and the variants of ground motion generation and propagation are combined with the logic tree approach. The presented mining-induced seismic hazard assessment method is illustrated be a practical example from Legnica-Głogow copper mining area in Poland.
| Item Type: | Book Section |
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| Subjects: | Region > Poland > Legnica-Glogow Copper District Inducing technology > Underground mining Methodology > Method and procesing |
| Project: | IS-EPOS project > LGCD: Regional seismicity and ground motion associating underground hard rock mining |