Development of a New Experimental Apparatus for the Study of the Mechanical Behaviour of a Rock Discontinuity Under Monotonic and Cyclic Loads

The shear behaviour of rock discontinuities in seismic condition is still not fully understood although earthquakes can be an important triggering cause of instability phenomena of rock blocks. For this purpose, a special apparatus was designed and developed at the University of Parma (Italy), which is to be placed inside the MTS press available in the Laboratory of Materials Testing. The press allows the application of monotonic and cyclic loads, in load or in deformation control. Quantitative evaluation of the rock-joint damage is realized by a photogrammetric survey of the discontinuity before and after the tests. The surface comparison enables the identification of the damaged areas. Finally, theoretical and experimental results are interpreted in the light of the damage model developed by Belem et al. (Rock Mech Rock Eng 33(4):217-242, 2001) for a quantitative evaluation of joint roughness and resistance.