The Influence of Cross-Section Shape on Failure of Rock Surrounding the Main Tunnel in a Water-Sealed Cavern

Yu Cong, Heyi Liu (), Xiaoshan Wang (), Defu Guo, Liliang Han, Yi Zhao and Lilei Zou
Additional contact information
Yu Cong: School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
Heyi Liu: Department of Geotechnical Engineering, China Institute of Water Resources and Hydropower Research, Beijing 100048, China
Xiaoshan Wang: School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
Defu Guo: The First Construction Division Co., Ltd. of China Railway Tunnel Group, Chongqing 401120, China
Liliang Han: CNPC East China Design Institute Co., Ltd., Qingdao 266071, China
Yi Zhao: CNPC East China Design Institute Co., Ltd., Qingdao 266071, China
Lilei Zou: CNPC East China Design Institute Co., Ltd., Qingdao 266071, China

Sustainability, 2022, vol. 15, issue 1, 1-14

Abstract: The influence of cross-section shape on rock stability was investigated by designing a similar model test and numerical simulation using particle flow code (PFC). The test results showed that the left- and right-hand sides of the entrance are subjected to tension, mainly forming vertical cracks or oblique cracks with a large dip angle. The vicinity of the entrance is subjected to the shear effect and the overall failure of the model is brittle in the similar test. Mesoscopic fractures mainly appear as tensile fractures, and a small number of shear fractures are found in the vicinity of the entrance. A long narrow coalescent-fracture zone is separately formed at the left- and right-hand sides of the entrance when approaching peak load in PFC test. Stress concentration occurs at the end of the long axis of the elliptic cross-section. The stress is high at the arch foot and spandrel of a horseshoe-shaped cross-section and a coalescent fracture zone formed at the arch foot on the right-hand side caused the tunnel to fail. The ovoid-shaped and vertical-wall-arched cross-sections are under significant tension, owing to the force chains distributed along the tunnel wall, show a large included angle with the tunnel wall. From the perspective of bearing capacity, a circle is the best section. From the perspective of failure mode, the horseshoe-shaped section is more suitable for use in corresponding practical engineering.

Keywords: physical model test; numerical simulation; mesoscopic fracture; tensile-shear coupling effect; force chain; failure mechanism (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2022
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/1/424/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/1/424/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2022:i:1:p:424-:d:1016259

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().