The Influence of a Local Fault Zone on High Energy Tremor Occurrence During Longwall Mining of a Coal Seam

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• 作者：Łukasz Wojtecki ; Małgorzata Knopik ; Wacław Marian Zuberek
• 关键词：Key wordsmine tremors ; focal mechanism ; seismic moment tensor ; underground coal mining
• 刊名：Acta Geophysica
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：64
• 期：4
• 页码：1164-1175
• 全文大小：434KB
• 刊物主题：Geophysics/Geodesy; Structural Geology; Geotechnical Engineering & Applied Earth Sciences;
• 出版者：Springer International Publishing
• ISSN：1895-7455
• 卷排序：64

文摘

Underground mining of coal seams in the Upper Silesian Coal Basin in Poland is accompanied by seismic activity of varying magnitude. The investigations which have been performed for several years distinguished high energy mine tremors connected directly with mining or coupled with geological structures, such as large faults. In mined seams, local fault zones occur. Faults in these zones are usually small, with throws comparable with coal seams thicknesses. Local fault zone may be responsible for the occurrence of high energy tremors as well as large faults, as presented in this article. An analysis of source mechanism of high energy tremors generated during longwall mining of the coal seam No. 510, with presence of a local fault zone, in one of the Polish hard coal mines in the Upper Silesian Coal Basin was performed. For this purpose, the seismic moment tensor inversion method was used. In most of foci, the process of shear predominated. Determined nodal plane parameters were correlated with parameters of faults forming the local fault zone. High energy tremors were generated mostly by dislocations on faults of the local fault zone. Weakening of roof rocks in the neighborhood of local fault zone takes an important role too, and was responsible for share of implosion in the focal mechanism.