Experimental and Numerical Investigation of Uniaxial Compression Failure in Rock-Like Specimens with L-shaped Nonpersistent Cracks

Abstract

The effect of L-shaped notches (nonpersistent cracks) on the behavior of distance between two pre-existing cracks, bridge area in rock-like specimens, has been investigated both experimentally and numerically in this study. In the first step, the Brazilian and biaxial tests were conducted and based on the experimental results, similar numerical models were calibrated, and the material properties for inputting into the numerical models were back-calculated. Then, the numerical models were calibrated based on the results of the experiments to make sure that both the experimental and numerical results match well. Eighteen rectangular models with dimension of 10 cm by 10 cm were built, and each model included two nonpersistent L-shaped cracks. The dominant type of crack found in both experiments and numerical models was found to be tensile. The fracturing patterns of the samples were mostly influenced by both the L-shaped crack length and the crack angularities, while the uniaxial strength of these samples was closely related to their fracturing shape and pattern. The numerical modeling provided additional insights on the development of shear cracks from nonpersistent joints that may have otherwise been invisible or undetectable based on the experimental results.