The purpose of the master's thesis was to develop and construct a direct shear device and to test its performance on rock samples for determining the geomechanical properties of discontinuities. Properties of discontinuities, such as roughness, shear angle, and uniaxial compressive strength, serve as essential input data for stability analyses of slopes in rock masses, making their understanding extremely important.
The study utilized Lower Cretaceous limestone samples collected from the G2-102/1034 Idrija–Godovič road section. The experimental part included point load index (PLT) tests and direct shear tests conducted in accordance with the applicable ISRM standard.
The methodology involved preparing the samples in the laboratory, embedding them in molds, and conducting tests under various loads to determine peak and residual shear strength. The shear tests were performed using a prototype device that enables the measurement of normal and shear forces as well as horizontal displacements. The test results were interpreted using existing theoretical failure models, such as the Mohr-Coulomb and Barton-Bandis models.
It was found that the new device is suitable for determining the shear strength of rock discontinuities, which is crucial for stability analyses of slopes and the planning of construction projects. However, as the device is still in its prototype phase, further improvements were suggested to fully meet the standards for conducting tests according to the current ISRM guidelines.
|
