JRMGE / Vol 17 / Issue 4
Influences of maximum principal stress direction and cross-section shape on tunnel stability
Xuefeng Si, Zilong Zhang, Xibing Li, Guansheng Yi, Yong Luo, Lihai Tan, Kaifeng Han
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a School of Resources Environment and Safety Engineering, University of South China, Hengyang, 421001, China
b Scientific and Technological Research Platform for Disaster Prevention and Control of Deep Coal Mining, Anhui University of Science and Technology,
Huainan, 232001, China
c School of Resources and Safety Engineering, Central South University, Changsha, 410083, China
d College of Meteorology and Oceanology, National University of Defense Technology, Changsha, 410073, China
2025, 17(4): 2159-2180. doi:10.1016/j.jrmge.2024.10.003
Received: 2024-05-23 / Revised: 2024-09-29 / Accepted: 2024-10-24 / Available online: 2024-10-28
2025, 17(4): 2159-2180.
doi:10.1016/j.jrmge.2024.10.003
Received: 2024-05-23
Revised: 2024-09-29
Accepted: 2024-10-24
Available online: 2024-10-28
To investigate the effects of the maximum principal stress direction (θ) and cross-section shape on the failure characteristics of sandstone, true-triaxial compression experiments were conducted using cubic samples with rectangular, circular, and D-shaped holes. As θ increases from 0° to 60° in the rectangular hole, the left failure location shifts from the left corner to the left sidewall, the left corner, and then the floor, while the right failure location shifts from the right corner to the right sidewall, right roof corner, and then the roof. Furthermore, the initial failure vertical stress first decreases and then increases. In comparison, the failure severity in the rectangular hole decreases for various θ values as 30° > 45° > 60° > 0°. With increasing θ, the fractal dimension (D) of rock slices first increases and then decreases. For the rectangular and D-shaped holes, when θ = 0°, 30°, and 90°, D for the rectangular hole is less than that of the D-shaped hole. When θ = 45° and 60°, D for the rectangular hole is greater than that of the D-shaped hole. Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas. The failure location rotates with the rotation of θ, and the failure occurs on the side with a high concentration of compressive stress, while the side with the tensile and compressive stresses remains relatively stable. Therefore, the fundamental reason for the rotation of failure location is the rotation of stress concentration, and the external influencing factor is the rotation of θ.
Keywords: Maximum principal stress direction, Cross-section shape, True-triaxial experiment, Failure characteristics, Fractal dimension, Theoretical analysis
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Author(s) Information
Xuefeng Si
Xuefeng Si received his PhD in geotechnical engineering from Central South University (CSU), China. He currently holds the position of distinguished professor at the School of Resources Environment and Safety Engineering, University of South China. His current research interests include the mechanism and prevention of underground engineering disasters, rock dynamics, and rock dynamic strength criteria. He has presided five projects form National Natural Science Foundation of China, Hunan Province, etc. He has honored with a second prize for natural science from the Ministry of Education, China, a first prize for green mining science and technology, and both first and third prizes for scientific and technological achievements from the China Gold Association. He has published 32 academic papers in renowned journals at home and abroad, including 8 ESI highly cited papers and 8 ESI hot papers. He has been granted 9 national invention patents.