Initial failure morphology of shallow loess containing millimeter-scale cracks: Insights from CT 3d imaging
- 1Institute of Disaster Prevention and Reduction of the Guangdong-Hong Kong-Macao Greater Bay Area, Guangdong University of Technology, Guangzhou, China
- 2School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, Guangdong, China
- 3School of Geological Engineering and Geomatics, Chang'an University, Xi'an, Shaanxi, China
Abstract
Frequent shallow loess slope failures in loess regions pose significant threats to both linear infrastructure and local communities. Millimeter-scale initial cracks induced by water, temperature, and weathering are key factors controlling such loess failures. Early diagnosis and prevention remain challenging, largely because the disaster chain triggered by millimeter-scale initial cracks is not fully understood, and the early failure behavior of these cracks is poorly characterized. In this study, laboratory experiments were conducted on loess specimens containing artificial millimeter-scale initial cracks to simulate natural cracks. Uniaxial compression tests combined with CT scanning were performed on specimens with initial cracks of varying characteristics. Three-dimensional structural models of the specimens at initial failure were reconstructed using machine learning methods, and the morphology and structural characteristics of the cracks were analyzed qualitatively and quantitatively. The test results show that the cracks generated in the initial failure state mainly involve wing cracks and extension cracks from the initial crack edges as well as wing cracks extending from both sides, initial cracks of varying characteristics produce different types of secondary cracks. Compared to intact specimens, samples with shallow, 45°-inclined, or shallow-surface compound cracks reached initial failure at substantially lower axial stresses—reduced by 78%, 65%, and 81%, respectively. This reduction is attributed to the development of larger-volume failure cracks in specimens with initial cracks. The distribution, inclination, and combination of millimeter-scale initial cracks exacerbate initial failure. Specifically, deeper initial cracks promote more large-volume failure cracks; 45° inclined initial cracks generate more large-volume failure cracks than horizontal or vertical ones; and two initial cracks produce more large-volume, large-diameter failure cracks than a single crack.
Related
- Was the mantle warmer when Pangea broke up? insights from initial oceanic crustal thickness alongside the rifted margins of the Atlantic and Indian Oceans
- Limestone exposures of North-West Laos containing Carboniferous or Permian fossils
- Pyridine-containing polymers/graphene oxide composites: synthesis, characterization, and application for the recovery of phenolic compounds
- Observation-constrained clear-sky direct radiative forcing of black carbon containing aerosols reveals distinct radiative regimes across urban Asia
- Quantifying nonlinear thresholds of grey-green space morphology on urban carbon metabolism across local climate zones: a machine learning study in Changchun city
BibTeX
@article{zhao2026initial,
title = {{Initial failure morphology of shallow loess containing millimeter-scale cracks: Insights from CT 3d imaging}},
author = {Luqing Zhao and Cuiying Zhou and Zhen Liu and Qingyi Mu and Penghui Ma and Jianbing Peng},
journal = {PLOS One},
year = {2026},
month = nov,
doi = {10.1371/journal.pone.0359832},
url = {https://doi.org/10.1371/journal.pone.0359832},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Initial failure morphology of shallow loess containing millimeter-scale cracks: Insights from CT 3d imaging
AU - Luqing Zhao
AU - Cuiying Zhou
AU - Zhen Liu
AU - Qingyi Mu
AU - Penghui Ma
AU - Jianbing Peng
PY - 2026
DA - 2026/11/05
JO - PLOS One
DO - 10.1371/journal.pone.0359832
UR - https://doi.org/10.1371/journal.pone.0359832
AB - Frequent shallow loess slope failures in loess regions pose significant threats to both linear infrastructure and local communities. Millimeter-scale initial cracks induced by water, temperature, and weathering are key factors controlling such loess failures. Early diagnosis and prevention remain challenging, largely because the disaster chain triggered by millimeter-scale initial cracks is not fully understood, and the early failure behavior of these cracks is poorly characterized. In this study, laboratory experiments were conducted on loess specimens containing artificial millimeter-scale initial cracks to simulate natural cracks. Uniaxial compression tests combined with CT scanning were performed on specimens with initial cracks of varying characteristics. Three-dimensional structural models of the specimens at initial failure were reconstructed using machine learning methods, and the morphology and structural characteristics of the cracks were analyzed qualitatively and quantitatively. The test results show that the cracks generated in the initial failure state mainly involve wing cracks and extension cracks from the initial crack edges as well as wing cracks extending from both sides, initial cracks of varying characteristics produce different types of secondary cracks. Compared to intact specimens, samples with shallow, 45°-inclined, or shallow-surface compound cracks reached initial failure at substantially lower axial stresses—reduced by 78%, 65%, and 81%, respectively. This reduction is attributed to the development of larger-volume failure cracks in specimens with initial cracks. The distribution, inclination, and combination of millimeter-scale initial cracks exacerbate initial failure. Specifically, deeper initial cracks promote more large-volume failure cracks; 45° inclined initial cracks generate more large-volume failure cracks than horizontal or vertical ones; and two initial cracks produce more large-volume, large-diameter failure cracks than a single crack.
SN - 1932-6203
ER -