Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata
[Objective] To control construction risks associated with deep metro station foundation pit in soil-rock composite strata, it is essential to analyze the stress characteristics of anchor cables and excavation-induced deformation during construction, formulate appropriate control measures accordingly...
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| Format: | Article |
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Urban Mass Transit Magazine Press
2025-06-01
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| Series: | Chengshi guidao jiaotong yanjiu |
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| Online Access: | https://umt1998.tongji.edu.cn/journal/paper/doi/10.16037/j.1007-869x.20230632.html |
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| author | SUN Chao XIN Qingfei SUN Zhicheng WU Yufei ZHOU Hao XU Dongming YANG Enze |
| author_facet | SUN Chao XIN Qingfei SUN Zhicheng WU Yufei ZHOU Hao XU Dongming YANG Enze |
| author_sort | SUN Chao |
| collection | DOAJ |
| description | [Objective] To control construction risks associated with deep metro station foundation pit in soil-rock composite strata, it is essential to analyze the stress characteristics of anchor cables and excavation-induced deformation during construction, formulate appropriate control measures accordingly, and verify their effectiveness on-site. [Method] Taking the deep foundation pit project construction at a metro station in Qingdao as a case study, non-destructive testing methods are employed to obtain the short- and long-term evolution law of anchor cable prestress. A 3D foundation pit–stratum model is developed using FLAC3D software to analyze the displacement of the retaining piles and the distribution characteristics of plastic zones under prestress loss conditions. The rationality of the support measures is verified based on pile displacement and steel strut axile force. [Result & Conclusion] Non-destructive testing results show that over 75% of the anchor cables passed the initial tensioning acceptance criteria. However, within 5 days, the prestress loss exceeded 10% of the lock-in value, indicating a relatively high level of short-term prestress loss. After the occurrence of prestress loss, the final horizontal displacement of the excavation is 2.5 times of the design value, with a maximum displacement of 35.4 mm, consistent with field monitoring results. Under conditions of low anchor cable prestress, wide and extensive plastic zones developed on both sides of the foundation pit, increasing the likelihood of the surrounding rock deformation. The installed steel struts shared part of the active earth pressure and altered the horizontal displacement distribution of the retaining piles. Following their deployment, the steel strut axile force initially increased, then gradually decreased, and eventually stabilized. The reinforcement measures of adding steel struts effectively controlled the deformation of the surrounding rock. |
| format | Article |
| id | doaj-art-af03331ee2ef4697a8e6ef29d1b3a11c |
| institution | Kabale University |
| issn | 1007-869X |
| language | zho |
| publishDate | 2025-06-01 |
| publisher | Urban Mass Transit Magazine Press |
| record_format | Article |
| series | Chengshi guidao jiaotong yanjiu |
| spelling | doaj-art-af03331ee2ef4697a8e6ef29d1b3a11c2025-08-20T03:29:23ZzhoUrban Mass Transit Magazine PressChengshi guidao jiaotong yanjiu1007-869X2025-06-01286879310.16037/j.1007-869x.20230632Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite StrataSUN Chao0XIN Qingfei1SUN Zhicheng2WU Yufei3ZHOU Hao4XU Dongming5YANG Enze6China Railway Fourth Bureau Group Co., Ltd., 230023, Hefei, ChinaChina Railway Fourth Bureau Group Co., Ltd., 230023, Hefei, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, 100083, Beijing, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, 100083, Beijing, ChinaChina Railway Fourth Bureau Group Co., Ltd., 230023, Hefei, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, 100083, Beijing, ChinaChina Railway Fourth Bureau Group Co., Ltd., 230023, Hefei, China[Objective] To control construction risks associated with deep metro station foundation pit in soil-rock composite strata, it is essential to analyze the stress characteristics of anchor cables and excavation-induced deformation during construction, formulate appropriate control measures accordingly, and verify their effectiveness on-site. [Method] Taking the deep foundation pit project construction at a metro station in Qingdao as a case study, non-destructive testing methods are employed to obtain the short- and long-term evolution law of anchor cable prestress. A 3D foundation pit–stratum model is developed using FLAC3D software to analyze the displacement of the retaining piles and the distribution characteristics of plastic zones under prestress loss conditions. The rationality of the support measures is verified based on pile displacement and steel strut axile force. [Result & Conclusion] Non-destructive testing results show that over 75% of the anchor cables passed the initial tensioning acceptance criteria. However, within 5 days, the prestress loss exceeded 10% of the lock-in value, indicating a relatively high level of short-term prestress loss. After the occurrence of prestress loss, the final horizontal displacement of the excavation is 2.5 times of the design value, with a maximum displacement of 35.4 mm, consistent with field monitoring results. Under conditions of low anchor cable prestress, wide and extensive plastic zones developed on both sides of the foundation pit, increasing the likelihood of the surrounding rock deformation. The installed steel struts shared part of the active earth pressure and altered the horizontal displacement distribution of the retaining piles. Following their deployment, the steel strut axile force initially increased, then gradually decreased, and eventually stabilized. The reinforcement measures of adding steel struts effectively controlled the deformation of the surrounding rock.https://umt1998.tongji.edu.cn/journal/paper/doi/10.16037/j.1007-869x.20230632.htmlmetrostation deep foundation pitsoil-rock composite strataanchor cable prestress lossdeformation control |
| spellingShingle | SUN Chao XIN Qingfei SUN Zhicheng WU Yufei ZHOU Hao XU Dongming YANG Enze Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata Chengshi guidao jiaotong yanjiu metro station deep foundation pit soil-rock composite strata anchor cable prestress loss deformation control |
| title | Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata |
| title_full | Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata |
| title_fullStr | Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata |
| title_full_unstemmed | Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata |
| title_short | Prestress Loss Law of Anchor Cables and Deformation Control for Metro Station Deep Foundation Pit in Soil-rock Composite Strata |
| title_sort | prestress loss law of anchor cables and deformation control for metro station deep foundation pit in soil rock composite strata |
| topic | metro station deep foundation pit soil-rock composite strata anchor cable prestress loss deformation control |
| url | https://umt1998.tongji.edu.cn/journal/paper/doi/10.16037/j.1007-869x.20230632.html |
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