Investigations into size dependence on the behavior of rocks with a “V” notch and hole under uniaxial compression

Abstract

This study employed a combination of experimental analysis and numerical simulations using the Particle Flow Code (PFC2D) to investigate the impact of interaction between porosity and V-shaped notch on the breakage behavior of gypsum-based rock-like samples. Also, the influence of scale effect on the notch-hole interaction has been investigated while the “<” notches were positioned at three different orientations (0°, 45°, and 90°) relative to the X-axis. Parallel to the experimental phase, nine samples with analogous “<” shape notches, as well as nine additional models featuring different “>” shape notches, were generated and assessed through numerical simulations. The findings indicate that crack propagation was primarily governed by the notch shape, asymmetric line angle, and model dimensions. Notably, the rock bridge located between the “<” shape notch and the hole exhibited significantly greater breakage compared to other notch configurations (i.e., “>” shape notch). Moreover, the volume of damage increased with the inclination of the asymmetric line and the model's dimensions. Both the angle of the asymmetric line and the model's size contributed to enhanced sample strength. Elevating the asymmetric line angle, simulation size, and V-shaped notch led to the creation of more fractures, consequently resulting in a heightened occurrence of failure events in rock-like materials. Delay failure occurred in models containing “>” shaped notch while abrupt failure occurred in models containing “<” shaped notch. The experimental results affirm that PFC2D faithfully replicated the sample's failure pattern and strength. This study is useful for rock engineering design when delay failure and or abrupt failure threaten the stability of rock engineering structures.