Showing papers in "International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts in 1979"

TL;DR: In this paper, the root mean square and the mean square of the first derivative of a surface profile were used to measure the joint roughness coefficient of the surface profiles presented by Barton and Choubey.

TL;DR: In this paper, a suitable machine for applying axial load to the specimen was proposed and verified at suitable time intervals and compliant with accepted national requirements such as prescribed in either ASTM Methods E4: Verification of Testing Machines or British Standard 1610, Grade A or Deutsche Normen DIN 51 220,DIN 51 223, Klasse 1 and DIN51 300.

TL;DR: In this article, the authors measured the permeability of whole and jointed Barre granite samples at pressures up to 2 kbar using split cylinders joined by surfaces with controlled surface roughness.

TL;DR: In this article, a scan electron microscope was used to study the growth and development of cracks in Barre granite under load, and the tensile character of stress-induced cracks and other observatios by Tapponnier and Brace were confirmed.

TL;DR: In this article, the authors studied the variation in discontinuity frequency as a function of scanline orientation in a plane for rock masses containing sets of discontinuities, and the spacing values between discontinuity intersection points that can occur along such scanlines were considered in order to develop a probability density distribution of block lengths.

TL;DR: In this paper, the authors studied the relationship between elastoplastic stress-strain relations with the current yield surface and the elastic modulus and showed that the rate response uniqueness and material stability of the elasticity modulus can be interpreted in mechanical terms using standard compression tests and for particular forms of constitutive laws.

TL;DR: In this paper, electron microscopy observations of stress-induced crack growth, causing crack-crack and crack-pore interactions within individual grains of Barre granite, show that photoelastic models of cracks are essentially correct and applicable to rock.

TL;DR: In this article, impact methods are used to create controlled dynamic fracture in Arkansas novaculite and laser interferometry is used to determine the time resolved stress during fracture Experimental fracture stresses and fracture energies are determined under varying dynamic tensile loading conditions.

TL;DR: In this paper, the authors consider the effect of post-failure characteristics on the phenomenon of destruction, give complete systems of equations for the theory of post failure deformations, and formulate criteria of stability and definitions adequate for the physical processes.

TL;DR: In this paper, the residual strength is defined as the surface roughness developed along the rock discontinuity during the failure process, and the term ultimate frictional resistance is used to describe the strength of the resulting roughness.

TL;DR: In this article, the authors describe several mechanisms that might cause, or at least contribute to, the failure of uniaxially compressed rock cylinders by sudden splitting parallel to the direction of loading.

TL;DR: In this paper, a model is presented employing assumption that time-dependent microcracking is responsible for the macroscopic viscoplastic deformation of rocks and the steady-state and tertiary creep stages (up to failure) are described by the simplified theory.

TL;DR: In this paper, a semi-infinite slab cooled on its face by liquid nitrogen is shown to have limited crack velocities due to the poor heat transfer rates associated with film boiling, and experiments on 10 cm cubes of Solnhofen limestone with liquid nitrogen injected into a central 5 cm long by 1 cm dia hole generally confirm the predictions.

TL;DR: In this article, the authors investigated the influence of environmental humidity and humidity path upon sample performance and concluded that the samples swelled in response to a combination of several mechanisms. But they did not consider the effect of pore air upon swelling pressure, and only minor contributions were attributed to hydration of expanding clay minerals and progressive strain energy release.

TL;DR: In this article, the minimum energy concepts, as applied to a granular material, are shown to be applicable to a blocky material representing a rock, and it is shown that there is a relationship between the principal stresses given in terms of the joint friction angle.

TL;DR: In this paper, a theory of wave propagation in shallow jointed rocks is presented, where elastic waves from a source are propagated around the tip of an open joint, and the depth of the joint is determined from known intercept times, wave velocities and joint spacing.

TL;DR: In this paper, the authors investigated the effect of macerals and rank of coal on respirable dust generation and found that low and medium volatile coals had high values for the specific rate of breakage distribution.

TL;DR: In this article, the development of microcracks and their influence on other physical properties of the rock are dependent on the dimensions of the crystal grains and their orientation is determined principally by the configuration of the crystals.

TL;DR: In this article, the authors describe how longitudinal and bending stress waves in percussive drill rods generate noise, and show that the largest noise source is the bending waves, which are mainly generated by imperfections in the piston, chuck, and drill rod alignment.

TL;DR: In this paper, a system of twelve equations have been developed for the elastic-plastic analysis of split-set roof bolts and these equations were programmed for solution on the IBM 370/168 computer.

TL;DR: In this paper, the authors measured the acoustic emission of Jinan gabbro and Changpin granite under triaxial compression over various stress paths (confining pressure up to 1.3 kb).

TL;DR: In this article, it is shown that moment transfer between blocks readily induces stress gradients within the intact material making up the blocks with a consequent development of tensile stresses, which readily creates an environment where the appropriate blocks may rupture.