Experimental and Numerical Research on 3D Crack Growth in Rocklike Material Subjected to Uniaxial Tension

Uniaxial tension experiments on precracked rocklike samples and the related numerical simulations using FRANC3D were performed to investigate the growth mechanism of three-dimensional (3D) cracks in rocks under tension as well as the strength and failure behavior of samples. Experimental results indicate that the geometric characteristics of preexisting cracks, including crack dip angle, crack spacing, and crack intensity, have significant effects on the strength and failure modes of the samples. Failure of samples resulted from the propagation of a single crack and the coalescence of multiple cracks if the spacing between adjacent cracks is less than the length of the cracks. Distribution of mixed-mode stress-intensity factors (SIFs) and energy-release rates (ERRs) along the fronts of cracks with different geometric characteristics was investigated numerically, and the results can provide an interpretation for the experimental results. Based on numerical simulations of the propagation processes of single and two parallel cracks, the growth patterns and growth rates of 3D cracks were studied. The simulation results of crack growth correspond well with the experimental phenomena. (C) 2013 American Society of Civil Engineers.