Abstract:To assess the main variables controlling the mechanical performance of argillaceous dolomite, this paper makes statistics on the inclination angle, length density and quantitative density of meso-cracks of argillaceous dolomite, and carries out electron microscope scanning test and uniaxial compression test. The results show that: (1) the average membership degree and weight of the microstructure of argillaceous dolomite are the largest, followed by the quantitative density of fissures, indicating that the microstructure has a great influence on the strength of rocks, followed by the quantitative density of fissures. Microstructure may be the most important factor affecting the strength of argillaceous dolomite. (2) the fracture dip angle makes the least contribution, with the fracture length density having the lowest average membership degree in comparison, indicating that although the latter two influencing factors have certain influence on rock strength, they are not the main factors affecting rock strength. (3) the variation coefficient CVj of the j index of uniaxial compressive strength of argillaceous dolomite is consistent with that of the comprehensive rock strength index RSI, while the value of stability coefficient SCj is just the opposite, the microstructure is the primary controlling factor for the rock's uniaxial compressive strength, and the diversification of microstructure will make the strength value of rock fluctuate greatly. This finding substantiates that microstructure serves as the principal determinant of rock strength.
