Experimental and numerical studies of rock-like specimens with different hole shapes under compressive-shear loading

Abstract

This paper investigates the influence of five hole shapes (ellipse, circle, trapezoid, inverted-U, and square) on the mechanical behavior and crack process of rock-like materials under compressive-shear loading. The study employs both laboratory experiments and discrete element method modeling. The results show that the presence and shape of holes significantly reduce load-bearing capacity of rock samples, particularly square holes with sharp corners, which can lead to crack propagation due to stress concentration. The progression of surface deformation, as captured by digital image correlation technology, provides additional insights into the nucleation and propagation of cracks. The numerical simulations show that elliptical hole samples exhibit the highest crack initiation load, while square hole samples exhibit the lowest. The ratio of crack initiation load to peak load remains constant for different hole shapes, ranging from 0.5 to 0.6. The findings of this study provide theoretical insight and practical evidence for rock engineering design and construction in compressive-shear environments.