Study on Dynamic Loading Characteristics of Rock Containing Holes

Abstract

Accurately characterizing the mechanical behavior and fracture mechanisms of rock containing holes under dynamic loads is essential for ensuring the stability of underground rock structures. In this study, to enhance the understanding of the fracture processes in rock specimens with cavities subjected to dynamic impacts, experimental and numerical studies focusing on the influence of borehole geometry and strain rate are conducted. The results reveal that the strain rate affects the specimens’ dynamic mechanical strength and peak strain. However, the degree of such influence diminishes as the borehole diameter increases in specimens containing two holes. Fractures that lead to failure are primarily initiated at the axial and radial edges of the holes, the specimen extremities, and around the rock bridges in specimens with dual cavities, indicating significant stress concentration zones within the stress field distribution for specimens with a single hole. Further analysis using displacement field diagrams confirms that shear-induced fractures are the predominant cause of failure across all specimens. These findings provide critical insights for developing borehole pressure relief technology to protect against the risks of deep dynamic impacts.