Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method
In multi-arch tunnels, the increased rock load on the concrete lining of the main tunnel and side walls due to the excavation of adjacent tunnels is critical and must be considered in the design stage. Therefore, this study estimates the rock load of a multi-arch tunnel using two-dimensional numeric...
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doaj-2add7c965dda4f90bc1d5e7c3fbadfc32020-11-25T02:11:12ZengMDPI AGApplied Sciences2076-34172020-05-01103285328510.3390/app10093285Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable MethodJae Kook Lee0Hankyu Yoo1Hoki Ban2Won-Jun Park3Department of Geotechnical Engineering, Saman Corporation, Gyeongggi-do 13837, KoreaDepartment of Civil and Environmental Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan 15588, KoreaDepartment of Civil Engineering, Kangwon National University, Samcheok 25913, KoreaDepartment of Architectural Engineering, Kangwon National University, Samcheok 25913, KoreaIn multi-arch tunnels, the increased rock load on the concrete lining of the main tunnel and side walls due to the excavation of adjacent tunnels is critical and must be considered in the design stage. Therefore, this study estimates the rock load of a multi-arch tunnel using two-dimensional numerical analysis, considering rock mass classifications, overburden, and construction steps. The rock load is estimated using two criteria: the factor of safety and stress variable. The rock load is underestimated when the factor of safety is applied to rock mass class III. However, the stress variable method reveals a reasonable rock load as overburden increases. Particularly, the rock load is estimated to be equal to the overburden in shallow tunnels and approximately 0.7 times the tunnel width in deep tunnels. Additionally, the crack-induced rock load is computed using back analysis at the excavation completion stage of adjacent tunnels, yielding the relation between the rock load height and the deformation modulus of the rock mass. Therefore, an accurate estimation of the rock load of multi-arch tunnels emphasizes the importance of a more economical and realistic design and must be addressed in the process of performance-based tunnel design.https://www.mdpi.com/2076-3417/10/9/3285multi-arch tunnelrock loadnumerical analysisfactor of safetystress variable |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jae Kook Lee Hankyu Yoo Hoki Ban Won-Jun Park |
spellingShingle |
Jae Kook Lee Hankyu Yoo Hoki Ban Won-Jun Park Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method Applied Sciences multi-arch tunnel rock load numerical analysis factor of safety stress variable |
author_facet |
Jae Kook Lee Hankyu Yoo Hoki Ban Won-Jun Park |
author_sort |
Jae Kook Lee |
title |
Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method |
title_short |
Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method |
title_full |
Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method |
title_fullStr |
Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method |
title_full_unstemmed |
Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method |
title_sort |
estimation of rock load of multi-arch tunnel with cracks using stress variable method |
publisher |
MDPI AG |
series |
Applied Sciences |
issn |
2076-3417 |
publishDate |
2020-05-01 |
description |
In multi-arch tunnels, the increased rock load on the concrete lining of the main tunnel and side walls due to the excavation of adjacent tunnels is critical and must be considered in the design stage. Therefore, this study estimates the rock load of a multi-arch tunnel using two-dimensional numerical analysis, considering rock mass classifications, overburden, and construction steps. The rock load is estimated using two criteria: the factor of safety and stress variable. The rock load is underestimated when the factor of safety is applied to rock mass class III. However, the stress variable method reveals a reasonable rock load as overburden increases. Particularly, the rock load is estimated to be equal to the overburden in shallow tunnels and approximately 0.7 times the tunnel width in deep tunnels. Additionally, the crack-induced rock load is computed using back analysis at the excavation completion stage of adjacent tunnels, yielding the relation between the rock load height and the deformation modulus of the rock mass. Therefore, an accurate estimation of the rock load of multi-arch tunnels emphasizes the importance of a more economical and realistic design and must be addressed in the process of performance-based tunnel design. |
topic |
multi-arch tunnel rock load numerical analysis factor of safety stress variable |
url |
https://www.mdpi.com/2076-3417/10/9/3285 |
work_keys_str_mv |
AT jaekooklee estimationofrockloadofmultiarchtunnelwithcracksusingstressvariablemethod AT hankyuyoo estimationofrockloadofmultiarchtunnelwithcracksusingstressvariablemethod AT hokiban estimationofrockloadofmultiarchtunnelwithcracksusingstressvariablemethod AT wonjunpark estimationofrockloadofmultiarchtunnelwithcracksusingstressvariablemethod |
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