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Discontinuity of rocks under uniaxial compression may be accompanied by a cleavage of one part relative to the other. Such a phenomenon is also observed in laboratory testing experiments. The cleavage area is geometrically an uneven rough surface. In modern practice, the level of roughness is usually characterized using the Barton-Choubey scale, where the visual profile of the discontinuity is correlated to the corresponding value of the joint roughness coefficient (JRC), varying in the range from 0 to 20. But in ...

The laboratory study was conducted to investigate the effect of the angle of stratification on the strength properties of samples of anisotropic shale and siltstone containing sandstone interlayers under shear loading with coupled compression in this paper. The samples of shale and siltstone were tested at various combinations of the orientation of bedding angles ? relative to the sample axis and the orientation of angles of shear plane ? relative to orientation of the stratification of samples. The experimental c...

Rocks can be structurally represented as layered bodies, whereby the layers can be located at different orientation angles with respect to the original ground. Such angles are usually called the bedding angles. To avoid mistakes in the calculations of the stress-strain state of rock massifs, it is very important to take into account the dependencies of mechanical properties of layered rocks on the bedding angle. Also, rocks are at a certain depth under hydrostatic compression conditions. For an adequate simulation...

Meta-siltstones are solid sedimentary rocks containing some clay material. Such geomaterial is taken mainly for the production of cement and garden paths. It can also be found in coal mines between coal beds. Processes of technological extraction of such natural material are always connected with the problems of its physical and mechanical behavior, therefore it is important to evaluate the basic deformation-strength properties. Moreover, if we consider the influence of the scale factor, we will get a more complet...

The authors have carried out uniaxial compression tests of 200 mm side cube specimens made of artificial layered geomaterial with the bedding angles of 0, 30, 45, 60 and 90 deg and with the different strength of the layers to study the process of deformation to failure using the multiparametric equipment designed for synchronous recording of physical fields of stresses, macrostrains, microseismic emission (MSE) and microstrains by speckle method. The integrated analyses of MSE signals, microstrains, stresses and s...