Research on Construction Sequencing and Deformation Control for Foundation Pit Groups

With the rapid urbanization and increasing development of underground spaces, foundation pit groups in complex geological environments encounter considerable challenges in deformation control. These challenges are especially prominent in cases of adjacent constructions, complex geology, and environm...

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Main Authors: Ziwei Yin, Ruizhe Jin, Shouye Guan, Zhiwei Chen, Guoliang Dai, Wenbo Zhu
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/15/14/7719
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author Ziwei Yin
Ruizhe Jin
Shouye Guan
Zhiwei Chen
Guoliang Dai
Wenbo Zhu
author_facet Ziwei Yin
Ruizhe Jin
Shouye Guan
Zhiwei Chen
Guoliang Dai
Wenbo Zhu
author_sort Ziwei Yin
collection DOAJ
description With the rapid urbanization and increasing development of underground spaces, foundation pit groups in complex geological environments encounter considerable challenges in deformation control. These challenges are especially prominent in cases of adjacent constructions, complex geology, and environmentally sensitive areas. Nevertheless, existing research is lacking in systematic analysis of construction sequencing and the interaction mechanisms between foundation pit groups. This results in gaps in comprehending stress redistribution and optimal excavation strategies for such configurations. To address these gaps, this study integrates physical model tests and PLAXIS 3D numerical simulations to explore the Nanjing Jiangbei New District Phase II pit groups. It concentrates on deformations in segmented and adjacent configurations under varying excavation sequences and spacing conditions. Key findings reveal that simultaneous excavation in segmented pit groups optimizes deformation control through symmetrical stress relief via bilateral unloading, reducing shared diaphragm wall displacement by 18–25% compared to sequential methods. Sequential excavations induce complex soil stress redistribution from asymmetric unloading, with deep-to-shallow sequencing minimizing exterior wall deformation (≤0.12%He). For adjacent foundation pit groups, simultaneous excavation achieves minimum displacement interference, while phased construction requires prioritizing large-section excavation first to mitigate cumulative deformations through optimized stress transfer. When the spacing-to-depth ratio (B/He) is below 1, horizontal displacements of retaining structures increase by 43% due to spacing effects. This study quantifies the effects of excavation sequences and spacing configurations on pit group deformation, establishing a theoretical framework for optimizing construction strategies and enhancing retaining structure stability. The findings are highly significant for underground engineering design and construction in complex urban geological settings, especially in high-density areas with spatial and geotechnical constraints.
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spelling doaj-art-ddd23ac96df34b939e55fba93d41d4082025-08-20T03:35:27ZengMDPI AGApplied Sciences2076-34172025-07-011514771910.3390/app15147719Research on Construction Sequencing and Deformation Control for Foundation Pit GroupsZiwei Yin0Ruizhe Jin1Shouye Guan2Zhiwei Chen3Guoliang Dai4Wenbo Zhu5School of Civil Engineering, Southeast University, Nanjing 210096, ChinaSchool of Civil Engineering, Southeast University, Nanjing 210096, ChinaChina Railway Construction Investment Group Corporation Limited, Zhuhai 519000, ChinaSchool of Civil Engineering, Southeast University, Nanjing 210096, ChinaSchool of Civil Engineering, Southeast University, Nanjing 210096, ChinaSchool of Civil Engineering, Southeast University, Nanjing 210096, ChinaWith the rapid urbanization and increasing development of underground spaces, foundation pit groups in complex geological environments encounter considerable challenges in deformation control. These challenges are especially prominent in cases of adjacent constructions, complex geology, and environmentally sensitive areas. Nevertheless, existing research is lacking in systematic analysis of construction sequencing and the interaction mechanisms between foundation pit groups. This results in gaps in comprehending stress redistribution and optimal excavation strategies for such configurations. To address these gaps, this study integrates physical model tests and PLAXIS 3D numerical simulations to explore the Nanjing Jiangbei New District Phase II pit groups. It concentrates on deformations in segmented and adjacent configurations under varying excavation sequences and spacing conditions. Key findings reveal that simultaneous excavation in segmented pit groups optimizes deformation control through symmetrical stress relief via bilateral unloading, reducing shared diaphragm wall displacement by 18–25% compared to sequential methods. Sequential excavations induce complex soil stress redistribution from asymmetric unloading, with deep-to-shallow sequencing minimizing exterior wall deformation (≤0.12%He). For adjacent foundation pit groups, simultaneous excavation achieves minimum displacement interference, while phased construction requires prioritizing large-section excavation first to mitigate cumulative deformations through optimized stress transfer. When the spacing-to-depth ratio (B/He) is below 1, horizontal displacements of retaining structures increase by 43% due to spacing effects. This study quantifies the effects of excavation sequences and spacing configurations on pit group deformation, establishing a theoretical framework for optimizing construction strategies and enhancing retaining structure stability. The findings are highly significant for underground engineering design and construction in complex urban geological settings, especially in high-density areas with spatial and geotechnical constraints.https://www.mdpi.com/2076-3417/15/14/7719geotechnical engineeringurban infrastructurefoundation pit groupsindoor physical experimentsnumerical simulation
spellingShingle Ziwei Yin
Ruizhe Jin
Shouye Guan
Zhiwei Chen
Guoliang Dai
Wenbo Zhu
Research on Construction Sequencing and Deformation Control for Foundation Pit Groups
Applied Sciences
geotechnical engineering
urban infrastructure
foundation pit groups
indoor physical experiments
numerical simulation
title Research on Construction Sequencing and Deformation Control for Foundation Pit Groups
title_full Research on Construction Sequencing and Deformation Control for Foundation Pit Groups
title_fullStr Research on Construction Sequencing and Deformation Control for Foundation Pit Groups
title_full_unstemmed Research on Construction Sequencing and Deformation Control for Foundation Pit Groups
title_short Research on Construction Sequencing and Deformation Control for Foundation Pit Groups
title_sort research on construction sequencing and deformation control for foundation pit groups
topic geotechnical engineering
urban infrastructure
foundation pit groups
indoor physical experiments
numerical simulation
url https://www.mdpi.com/2076-3417/15/14/7719
work_keys_str_mv AT ziweiyin researchonconstructionsequencinganddeformationcontrolforfoundationpitgroups
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AT zhiweichen researchonconstructionsequencinganddeformationcontrolforfoundationpitgroups
AT guoliangdai researchonconstructionsequencinganddeformationcontrolforfoundationpitgroups
AT wenbozhu researchonconstructionsequencinganddeformationcontrolforfoundationpitgroups