Micro‑Fracturing in Granitic Rocks During Uniaxial Loading: The Role of Grain Size Heterogeneity

0579238 - GLÚ 2025 RIV DE eng J - Journal Article
Petružálek, Matěj - Jechumtálová, Zuzana - Lokajíček, Tomáš - Kolář, Petr - Šílený, Jan
Micro‑Fracturing in Granitic Rocks During Uniaxial Loading: The Role of Grain Size Heterogeneity.
Rock Mechanics and Rock Engineering. Roč. 57, č. 3 (2024), s. 1963-1981. ISSN 0723-2632. E-ISSN 1434-453X
R&D Projects: GA ČR(CZ) GA21-26542S; GA ČR(CZ) GA22-00580S
Institutional support: RVO:67985831 ; RVO:67985530
Keywords : Uniaxial compressive test * Fracturing * Grain size heterogeneity * Acoustic emission * Source mechanism * Granite
OECD category: Environmental and geological engineering, geotechnics; Environmental and geological engineering, geotechnics (GFU-E)
Impact factor: 6.2, year: 2022
Method of publishing: Limited access
https://doi.org/10.1007/s00603-023-03668-7

Laboratory loading experiments, in general, are used to estimate the mechanical properties of rocks. The application of acoustic emission (AE), a proxy for very small-scale earthquakes, offers insights into rock fracturing, especially when advanced seismological methods are applied. The uniaxial compressive test, the most conventional test within the scope of laboratory rock mechanics, estimates strength, elastic constants, or microcracking thresholds. Obviously, rock structure and grain size heterogeneity are the crucial parameters controlling these mechanical properties. Here, four granites with a different structure were uniaxially loaded, while AE was monitored, in order to observe the manner of fracturing. AE data were utilized at three different quality levels (AE recognition, AE localization, and the AE source mechanism). However, our focus was to study AE source mechanisms via the application of a shear-tensile crack source model. During a uniaxial compressive test, common (structurally independent) AE features led to the general characterization of microfracturing. On the other hand, sample related differences in AE results are discussed with respect to the role of granite heterogeneity. The comprehensiveness of the AE application demonstrated the validity of various levels of AE experiments.
Permanent Link: https://hdl.handle.net/11104/0352375