Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters

Deep-buried soft rock tunnels exhibit low strength and easy deformation under the influence of high ground stress. The surrounding rock of the soft rock tunnel may undergo large deformation during the construction process, thereby causing engineering problems such as the collapse of the vault, botto...

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Main Authors: Hao Wu, Xiaohua Yang, Shichun Cai, Binjing Zhao, Kunlong Zheng
Format: Article
Language:English
Published: Wiley 2021-01-01
Series:Advances in Civil Engineering
Online Access:http://dx.doi.org/10.1155/2021/8824793
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author Hao Wu
Xiaohua Yang
Shichun Cai
Binjing Zhao
Kunlong Zheng
author_facet Hao Wu
Xiaohua Yang
Shichun Cai
Binjing Zhao
Kunlong Zheng
author_sort Hao Wu
collection DOAJ
description Deep-buried soft rock tunnels exhibit low strength and easy deformation under the influence of high ground stress. The surrounding rock of the soft rock tunnel may undergo large deformation during the construction process, thereby causing engineering problems such as the collapse of the vault, bottom heave, and damage to the supporting structure. The Chengwu Expressway Tunnel II, considered in this study, is a phyllite tunnel, with weak surrounding rock and poor water stability. Under the original design conditions, the supporting structure exhibits stress concentration and large deformation. To address these issues, three schemes involving the use of the double-layer steel arch to support, weakening of the steel arch close to the excavation surface, and weakening of the steel arch away from the excavation surface to support were proposed. Using these schemes, the inverted radius was varied to explore its influence on different support schemes. For simulation, the values of the inverted radius selected were as follows: 1300 cm, 1000 cm, and 700 cm. The proposed support plan was simulated using FLAC3D, and the changes in the pressure between the initial support and surrounding rock, the settling of the vault, and the surrounding convergence were investigated. The numerical simulation results of monitoring the surrounding rock deformation show that the double-layer steel arch can effectively reduce the large deformation of the soft rock well. When the stiffness of one of the steel arches was weakened, the support’s ability to control the deformation was weakened; however, it still showed reliable performance in controlling deformation. However, changing the radius of the invert had an insignificant effect on the deformation and force of the supporting structure.
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language English
publishDate 2021-01-01
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series Advances in Civil Engineering
spelling doaj-art-246bcacccdd449e9a78e7f69acd963242025-08-20T03:54:52ZengWileyAdvances in Civil Engineering1687-80861687-80942021-01-01202110.1155/2021/88247938824793Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support ParametersHao Wu0Xiaohua Yang1Shichun Cai2Binjing Zhao3Kunlong Zheng4School of Highway, Chang’an University, Xi’an 710064, ChinaSchool of Highway, Chang’an University, Xi’an 710064, ChinaSchool of Highway, Chang’an University, Xi’an 710064, ChinaSchool of Highway, Chang’an University, Xi’an 710064, ChinaSchool of Highway, Chang’an University, Xi’an 710064, ChinaDeep-buried soft rock tunnels exhibit low strength and easy deformation under the influence of high ground stress. The surrounding rock of the soft rock tunnel may undergo large deformation during the construction process, thereby causing engineering problems such as the collapse of the vault, bottom heave, and damage to the supporting structure. The Chengwu Expressway Tunnel II, considered in this study, is a phyllite tunnel, with weak surrounding rock and poor water stability. Under the original design conditions, the supporting structure exhibits stress concentration and large deformation. To address these issues, three schemes involving the use of the double-layer steel arch to support, weakening of the steel arch close to the excavation surface, and weakening of the steel arch away from the excavation surface to support were proposed. Using these schemes, the inverted radius was varied to explore its influence on different support schemes. For simulation, the values of the inverted radius selected were as follows: 1300 cm, 1000 cm, and 700 cm. The proposed support plan was simulated using FLAC3D, and the changes in the pressure between the initial support and surrounding rock, the settling of the vault, and the surrounding convergence were investigated. The numerical simulation results of monitoring the surrounding rock deformation show that the double-layer steel arch can effectively reduce the large deformation of the soft rock well. When the stiffness of one of the steel arches was weakened, the support’s ability to control the deformation was weakened; however, it still showed reliable performance in controlling deformation. However, changing the radius of the invert had an insignificant effect on the deformation and force of the supporting structure.http://dx.doi.org/10.1155/2021/8824793
spellingShingle Hao Wu
Xiaohua Yang
Shichun Cai
Binjing Zhao
Kunlong Zheng
Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters
Advances in Civil Engineering
title Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters
title_full Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters
title_fullStr Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters
title_full_unstemmed Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters
title_short Analysis of Stress and Deformation Characteristics of Deep-Buried Phyllite Tunnel Structure under Different Cross-Section Forms and Initial Support Parameters
title_sort analysis of stress and deformation characteristics of deep buried phyllite tunnel structure under different cross section forms and initial support parameters
url http://dx.doi.org/10.1155/2021/8824793
work_keys_str_mv AT haowu analysisofstressanddeformationcharacteristicsofdeepburiedphyllitetunnelstructureunderdifferentcrosssectionformsandinitialsupportparameters
AT xiaohuayang analysisofstressanddeformationcharacteristicsofdeepburiedphyllitetunnelstructureunderdifferentcrosssectionformsandinitialsupportparameters
AT shichuncai analysisofstressanddeformationcharacteristicsofdeepburiedphyllitetunnelstructureunderdifferentcrosssectionformsandinitialsupportparameters
AT binjingzhao analysisofstressanddeformationcharacteristicsofdeepburiedphyllitetunnelstructureunderdifferentcrosssectionformsandinitialsupportparameters
AT kunlongzheng analysisofstressanddeformationcharacteristicsofdeepburiedphyllitetunnelstructureunderdifferentcrosssectionformsandinitialsupportparameters