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Lomová houževnatost hornin a vliv rychlosti zatěžování v módu I
Vavro, Leona
The presented paper presents another results of the rocks fracture toughness measurement. The influence of the loading velocity on the fracture parameters was investigated. The loading velocity was continually changed in values 1; 0,1 a 0,01 mm/s. The measurements were realized on selected rocks in the laboratory conditions in the Institute of Geonics AS CR.
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Test equipment for measurement of the rock fracture toughness
Vavro, Leona
Presented contribution provides basic knowledge of development in the methodology of rock fracture toughness measurement in the laboratories of the Institute of Geonics AS CR in Ostrava. Fracture toughness is a relatively new parameter in geomechanics; the laboratory preparation of rock specimen is very time consuming. The fracture toughness of rocks may be practically used in a wide range of application; e.g. prediction of the anomalies in the geomechanics processes like the rock bumps.
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The effect of anisotropy and mineral composition on phase transformation and rock thermal expansion
Plevová, Eva
Grantový projekt byl zaměřen na posouzení vlivů složení a stavby hornin na jejich teplotní roztažnost spolu s vlivem fázových změn a dalších reakcí probíhajících v systému během tepelného namáhání daného materiálu. Cílem projektu byl návrh metodiky stanovení tepelné roztažnosti hornin v závislosti na jejich složení a stavbě. K analýzám byly vybrány a dále testovány 3 geneticky odlišné typy hornin : pískovce, mramory a žuly. Výsledky grantového projektu potvrdily, že metoda simultánní termogravimetrické a diferenciální termické analýzy spolu s metodou termomechanické analýzy může být efektivně využívána v oblasti výzkumu hornin a především v oblasti studia jejich tepelně-mechanických vlastností.
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Turning by high-speed abrasive water jet – our experiences
Sitek, Libor
The paper describes and analyses our own experiences concerning technology of turning by high speed abrasive water jet. Technology development as well as present stay-of–the-art in given area are introduced in brief. Possibilities of application of such machining method especially for shaping and preparation of testing rock specimens suitable for determination of physical-mechanical properties of rocks are also discussed.
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Contribution to the up to date state of the rock fracture toughness measurement
Vavro, Leona
Presented contribution gives basic knowledge of the development in the methodology of rock fracture toughness measurement in the laboratories of the Institute of Geonics AS CR in Ostrava. So far, there have been taken samples of three basic types of rocks (e. g. granite, sandstone, marble) and in the present times there are being prepared the specimen for the rock fracture toughness measurement using the method 1 of the first test level. There were realized the first measurements and according to their results there were calculated the real values of fracture toughness of chosen rock samples.
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Contribution to the fracture toughness of rocks and to its measurement metodology
Vavro, Leona
Considering the fracture rock mechanics in the Czech Republic it is in contrast with the fracture mechanics of concrete, metal, plastic or ceramics relatively less explored area. Presented contribution gives basic knowledge of the development in the methodology of rock fracture toughness measurement in the laboratories of the Institute of Geonics AS CR in Ostrava. The measurement methodology comes out of Publisher reference in International Society for Rock Mechanic. So far, then have been taken samples of basic types of rocks (e. g. granite, sandstone, marble). In the present times there are made the microsections for microscopic study of the mineral – petrology composition and also there are determined basic physical and mechanical properties of rocks. In the following part of the research will be prepared the specimen for the rock fracture toughness measurement, which will be assessed according to the used methodology. The fracture toughness of rocks may be practically used in a wide range of applications; e.g. prediction of the anomalies in the geomechanics processes like the rock bumps.
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