Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition

In this investigation, deformations of a deep foundation pit in hard rock strata, respectively, under delayed and in-time supporting schemes of one-layer transverse reinforced concrete bracings at the top of the foundation pit, one-layer steel bracings at a depth of 8 m, and one-layer prestressed an...

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Main Authors: Yang Li, Zhanguo Ma, Furong Gao, Peng Gong, Zhiqun Gong, Kelong Li
Format: Article
Language:English
Published: Wiley 2023-01-01
Series:Shock and Vibration
Online Access:http://dx.doi.org/10.1155/2023/5155504
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author Yang Li
Zhanguo Ma
Furong Gao
Peng Gong
Zhiqun Gong
Kelong Li
author_facet Yang Li
Zhanguo Ma
Furong Gao
Peng Gong
Zhiqun Gong
Kelong Li
author_sort Yang Li
collection DOAJ
description In this investigation, deformations of a deep foundation pit in hard rock strata, respectively, under delayed and in-time supporting schemes of one-layer transverse reinforced concrete bracings at the top of the foundation pit, one-layer steel bracings at a depth of 8 m, and one-layer prestressed anchorages at a depth of 22.5 m during excavation were characterized according to lateral deformations of the foundation pit, settlements of the surrounding ground, and axial forces of the steel bracings according to numerical calculations and on-site monitoring. Numerical calculation results showed that the maximum lateral deformations of the foundation pit and settlements of the surrounding ground were, respectively, 10.34 mm and 8.49 mm at an excavation depth of 31 m, which were obviously larger than those under in-time supporting. Meanwhile, under delayed supporting conditions, lateral deformations of the foundation pit and settlements of the surrounding ground were far less than the allowed values, respectively, being 0.3% and 0.15% of the excavation depth, required in the Chinese standard of GB50007-2011, indicating that the foundation pit under delayed supporting conditions had good stability. Therefore, when excavating deep foundation pits in hard rock strata, proper delayed supporting schemes could be considered so that strengths of the surrounding hard rocks could be utilized to the fullest, and at the same time, more spaces for excavation could be freed up, and construction duration and construction costs could thus be lowered.
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institution Kabale University
issn 1875-9203
language English
publishDate 2023-01-01
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record_format Article
series Shock and Vibration
spelling doaj-art-b1ea5921668b4f68be0cbad66ed03e162025-08-20T03:39:18ZengWileyShock and Vibration1875-92032023-01-01202310.1155/2023/5155504Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting ConditionYang Li0Zhanguo Ma1Furong Gao2Peng Gong3Zhiqun Gong4Kelong Li5State Key Laboratory for Geomechanics and Deep Underground EngineeringState Key Laboratory for Geomechanics and Deep Underground EngineeringState Key Laboratory for Geomechanics and Deep Underground EngineeringState Key Laboratory for Geomechanics and Deep Underground EngineeringState Key Laboratory for Geomechanics and Deep Underground EngineeringState Key Laboratory for Geomechanics and Deep Underground EngineeringIn this investigation, deformations of a deep foundation pit in hard rock strata, respectively, under delayed and in-time supporting schemes of one-layer transverse reinforced concrete bracings at the top of the foundation pit, one-layer steel bracings at a depth of 8 m, and one-layer prestressed anchorages at a depth of 22.5 m during excavation were characterized according to lateral deformations of the foundation pit, settlements of the surrounding ground, and axial forces of the steel bracings according to numerical calculations and on-site monitoring. Numerical calculation results showed that the maximum lateral deformations of the foundation pit and settlements of the surrounding ground were, respectively, 10.34 mm and 8.49 mm at an excavation depth of 31 m, which were obviously larger than those under in-time supporting. Meanwhile, under delayed supporting conditions, lateral deformations of the foundation pit and settlements of the surrounding ground were far less than the allowed values, respectively, being 0.3% and 0.15% of the excavation depth, required in the Chinese standard of GB50007-2011, indicating that the foundation pit under delayed supporting conditions had good stability. Therefore, when excavating deep foundation pits in hard rock strata, proper delayed supporting schemes could be considered so that strengths of the surrounding hard rocks could be utilized to the fullest, and at the same time, more spaces for excavation could be freed up, and construction duration and construction costs could thus be lowered.http://dx.doi.org/10.1155/2023/5155504
spellingShingle Yang Li
Zhanguo Ma
Furong Gao
Peng Gong
Zhiqun Gong
Kelong Li
Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition
Shock and Vibration
title Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition
title_full Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition
title_fullStr Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition
title_full_unstemmed Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition
title_short Deformation Characteristics of a Deep Subway Foundation Pit in Hard Rock Strata under a Delayed Supporting Condition
title_sort deformation characteristics of a deep subway foundation pit in hard rock strata under a delayed supporting condition
url http://dx.doi.org/10.1155/2023/5155504
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AT penggong deformationcharacteristicsofadeepsubwayfoundationpitinhardrockstrataunderadelayedsupportingcondition
AT zhiqungong deformationcharacteristicsofadeepsubwayfoundationpitinhardrockstrataunderadelayedsupportingcondition
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