Fatigue damage response of typical crystalline and granular rocks to uniaxial cyclic compression

The effect of cyclic loading on the fatigue life, deformation properties and damage mechanisms of two microstructurally different rock types is explored by conducting uniaxial monotonic and cyclic compression tests under different loading conditions. Results show greater damage effects of low-frequency cyclic loading on the crystalline rock than on the granular rock. The damage evolution is characterized by introducing a damage variable based on residual strain. The results also indicate that damage evolution in the axial direction is different from that in the lateral direction. The development of many tensile microcracks is the main response of rocks to cyclic loading conditions.