The Fifth International Symposium on Mine Safety Science and Engineering (ISMSSE2021)

49 / 2021-08-27 16:45:21

Experimental Study on Crack Evolution and Fracture Simulation of Large-size Rock Samples

Large-size Rock Samples; Crack Evolution; Acoustic Emission; Secondary Coplanar crack

Abstract: The mine disaster is the result of quantitative to qualitative change in the evolution of rock cracks. In this paper, single-crack and double-crack loading tests were conducted on large-size rock samples of 400mm×200mm×200mm to analyze the crack evolution characteristics with different crack geometric properties. The study shows that similar rupture processes occur in the loading process of large size rock samples with single and double cracks with five main characteristics of crack initiation, crack expansion tending to the direction of stress loading, rupture point appearing in the middle of the bottom of the sample, secondary coplanar crack appearing at the tip of the crack, and final rupture of the sample, and four coalescence patterns between cracks, and it is also known to us that the appearance of secondary coplanar cracks is the precursor of sudden rupture of large size rock samples. The results are of great significance to the destabilization of underground rock projects and disaster prevention and control.