Study on the Deformation and Energy Evolution of Skarn With Marble Band of Different Orientations Under Cyclic Loading: A Lab-Scale Study

The aim of this work is to investigate the deformation and energy characteristics of skarn with different interlayer inclination angles under cyclic loading. The skarn samples with marble bands of various orientations (i.e., 30°, 45°, 60°, and 75°) were chosen as the test material. It is revealed from the testing results that the presence of interlayers changes the geomechanical properties of the rock, rock peak strength, and elastic modulus increases with increasing the interlayer inclination angle. Additionally, the growth rate of input energy exhibits an inverted “V” pattern with respect to the interlayer inclination angle. In terms of damage modes, intact marble and skarn predominantly exhibit tensile damage, whereas interlayered rocks exhibit a combination of tensile and shear failure pattern. Finally, a damage evolution model defined by axial strain is proposed and expressed to fit the experimental data. The results in this work would provide a crucial theoretical basis for the safety assessment of underground engineering constructions.