Effect of strength anisotropy on schist rocks and slope stability analysis

In engineering works such as open and underground mining operations, the anisotropic property of the rock plays an important role in stability. This feature is evaluated according to the results obtained from measurements taken perpendicular to the layer planes or at random angles. However, mechanical, physical and other properties of anisotropic rocks take different values according to the angle of the anisotropy plane with the vertical plane. For this reason, the effect of strength anisotropy should be examined in engineering studies. In this study, the effect of directionally changing the anisotropic properties of the metamorphic rock mass (greenschist and mica schist), which is thought to cause instability, on the slope stability at the copper mine site located in the Hanönü district of Kastamonu, Turkey, were investigated. In order to evaluate the effect, Generalised Hoek–Brown, Mohr–Coulomb, Anisotropic Linear and Snowden Anisotropic Linear failure criteria were used at different orientation angles. For this purpose, mechanical and physical tests were carried out on samples with orientation angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°. The data obtained from the experimental studies were evaluated separately at the different orientation angles, the slope stability analyses were performed and the appropriate slope safety results were found for the site. In general, maximum slope safety result values at 60° and minimum at 0° were obtained. In addition, appropriate slope angle, width and height are suggested in line with the slope safety results obtained.