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Failure character of coal geo-composites grouting resins base
Souček, Kamil ; Staš, Lubomír ; Obara, Y. ; Fukahori, D.
One of the possibilities of improving stability of longwall gates and roadway driven in coal seams in the application of a chemical grouting that will result in formation of a coal geocomposite in the surroudings of the underground roadway. The properties of such a coal geocomposite differ from the ones of the unmodified coal seam. The presented paper deals with laboratory geo-mechanical tests of pure coal and coal geo-composites prepared in laboratory. The paper discusses the different failure of these original and modified coal samples. The X-ray CT scans were used for observation and demonstration of failure evolution in these samples of pure coal and coal geo-composites.
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Horizontal stress in Czech part of Upper Silesian Basin
Staš, Lubomír ; Kolcun, Alexej ; Šimkovičová, Jarmila ; Souček, Kamil
The results of measurement by hydrofracturing method in the area of Czech part of USB are discussed. The measurements proved some general direction of the primary stress impact: high anisotrophy of horizontal stress, relatively high ratio of horizontal to vertical stresses ((SH+Sh)/Sv÷2). Horizontal stresses in the zones intensely disturbed by mining activity indicate magnitudes corresponding only to effect of overburden load in elastic model of rock mass. Orientation of horizontal stress either corresponds direction of presumed effect of superposition of Carpathian nappes or copiers direction of vicinity tectonic faults usually near of them.
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