The influence of the ratio of dimensions of rock samples on their tensile strength

Abstract

Annotation In the work, studies were carried out on the effect of the dimensions of rock samples and the shape of their end faces on the tensile strength limits. Sandstones, aleurolites and their interlayers were tested. The core diameter was 36-78 mm, prevailing 50-70 mm. Rocks are mainly me- dium- and fine-grained. The fracture of cores into pieces took place along thin layers of carbonaceous materials, aleurolites, cracks and cleavage, in places of accumulation and plaque of carbonaceous, carbonate and other weak substances in the form of continuous films, scattered spots and debris. All tests were carried out on the press in accordance with the recommenda- tions of the current GOST, samples were divided by applying a load along the generatrix. It was found that the tensile strength of the test samples var- ied from 0.15 to 21 MPa. The results obtained proved conclusively that cores can be used to solve production and technical problems without pre- liminary treatment of their end surfaces at the ratio of heights to diameters from 0.31 to 1.6. This will allow to increase the volume of tests of samples taken in wells by 60%, and obtain reliable information and thus more fully and reliably substantiate geomechanical conditions, Attachment and protec- tion of mine workings and optimal angles of slopes of quarry sides and ledges at open method of coal mining. This issue has been little studied and requires further research in every geological-economic region of Kuzbass.