Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels

This study aims to solve the problem of stability of the excavation surface of a new tunnel crossing an existing tunnel orthogonally. The relative horizontal spacing between the two tunnels is taken as an influencing factor, and transparent soil model tests are conducted and expanded with numerical...

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Main Authors: Shaokun Ma, Zhang Zhou, Zhibo Duan, Zhen Huang, Benfu He, Pengtao An, Jinmei Li
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/14/22/10521
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author Shaokun Ma
Zhang Zhou
Zhibo Duan
Zhen Huang
Benfu He
Pengtao An
Jinmei Li
author_facet Shaokun Ma
Zhang Zhou
Zhibo Duan
Zhen Huang
Benfu He
Pengtao An
Jinmei Li
author_sort Shaokun Ma
collection DOAJ
description This study aims to solve the problem of stability of the excavation surface of a new tunnel crossing an existing tunnel orthogonally. The relative horizontal spacing between the two tunnels is taken as an influencing factor, and transparent soil model tests are conducted and expanded with numerical simulations. Finally, the active destabilization mechanism and influence characteristics of the excavation surface of the two tunnels at different horizontal spacings, vertical spacings, and tunnel diameter ratios are obtained. The results show that when the excavated face is destabilized, the existing tunnel located in front of and above the excavation surface limits the development of the upper “silo” and the transfer of soil stress in the destabilized area, and the ultimate support pressure is reduced by 17.6% and 8.7%, respectively. This effect increases as the vertical spacing between the two tunnels decreases and the tunnel diameter ratio increases. At this point, the deformation trend of the existing tunnel cross-section is reflected as “elliptical-shaped”. This trend is more apparent when the vertical spacing between the two tunnels and the tunnel diameter ratio are decreased. The protection of the existing tunnel should be strengthened at this time.
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institution Kabale University
issn 2076-3417
language English
publishDate 2024-11-01
publisher MDPI AG
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series Applied Sciences
spelling doaj-art-ffc10b23ae6c46dd9035281a3bc47b1b2024-11-26T17:49:05ZengMDPI AGApplied Sciences2076-34172024-11-0114221052110.3390/app142210521Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing TunnelsShaokun Ma0Zhang Zhou1Zhibo Duan2Zhen Huang3Benfu He4Pengtao An5Jinmei Li6School of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaDepartment of Civil Engineering, Tsinghua University, Beijing 100084, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, ChinaThis study aims to solve the problem of stability of the excavation surface of a new tunnel crossing an existing tunnel orthogonally. The relative horizontal spacing between the two tunnels is taken as an influencing factor, and transparent soil model tests are conducted and expanded with numerical simulations. Finally, the active destabilization mechanism and influence characteristics of the excavation surface of the two tunnels at different horizontal spacings, vertical spacings, and tunnel diameter ratios are obtained. The results show that when the excavated face is destabilized, the existing tunnel located in front of and above the excavation surface limits the development of the upper “silo” and the transfer of soil stress in the destabilized area, and the ultimate support pressure is reduced by 17.6% and 8.7%, respectively. This effect increases as the vertical spacing between the two tunnels decreases and the tunnel diameter ratio increases. At this point, the deformation trend of the existing tunnel cross-section is reflected as “elliptical-shaped”. This trend is more apparent when the vertical spacing between the two tunnels and the tunnel diameter ratio are decreased. The protection of the existing tunnel should be strengthened at this time.https://www.mdpi.com/2076-3417/14/22/10521shield tunnelexcavation surface stabilityexisting tunnelsorthogonal underpasstransparent soil
spellingShingle Shaokun Ma
Zhang Zhou
Zhibo Duan
Zhen Huang
Benfu He
Pengtao An
Jinmei Li
Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels
Applied Sciences
shield tunnel
excavation surface stability
existing tunnels
orthogonal underpass
transparent soil
title Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels
title_full Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels
title_fullStr Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels
title_full_unstemmed Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels
title_short Study on the Influence Characteristics of Excavation Face Instability of New Tunnels Orthogonally Crossing Existing Tunnels
title_sort study on the influence characteristics of excavation face instability of new tunnels orthogonally crossing existing tunnels
topic shield tunnel
excavation surface stability
existing tunnels
orthogonal underpass
transparent soil
url https://www.mdpi.com/2076-3417/14/22/10521
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AT zhangzhou studyontheinfluencecharacteristicsofexcavationfaceinstabilityofnewtunnelsorthogonallycrossingexistingtunnels
AT zhiboduan studyontheinfluencecharacteristicsofexcavationfaceinstabilityofnewtunnelsorthogonallycrossingexistingtunnels
AT zhenhuang studyontheinfluencecharacteristicsofexcavationfaceinstabilityofnewtunnelsorthogonallycrossingexistingtunnels
AT benfuhe studyontheinfluencecharacteristicsofexcavationfaceinstabilityofnewtunnelsorthogonallycrossingexistingtunnels
AT pengtaoan studyontheinfluencecharacteristicsofexcavationfaceinstabilityofnewtunnelsorthogonallycrossingexistingtunnels
AT jinmeili studyontheinfluencecharacteristicsofexcavationfaceinstabilityofnewtunnelsorthogonallycrossingexistingtunnels