Field investigation on heave behavior of pile groups induced by deep excavation
LI Jian1, QIN Shanglin1, LI Shichang2, YU Fei1*, DAI Zhangjun1
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering Safety, Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences, Wuhan, Hubei 430071, China; 2. School of Civil Engineering,
Henan Polytechnic University, Jiaozuo, Henan 454003, China)
Abstract：To investigate the heave deformation law of group pile foundations under deep excavation conditions, this study is conducted based on the background of an actual high-speed railway bridge project. A full-scale field model test of group pile foundations with dimensions completely consistent with the engineering prototype is carried out. Through precise monitoring and systematic analysis, the deformation characteristics, force transmission laws, and key influencing factors of group pile foundations under deep excavation conditions are thoroughly revealed. The test results show that soil unloading rebound is the core inducement of heave deformation of pile foundations under deep excavation. When the excavation depth of the soil around the pile foundations reaches 9.5 m, the maximum heave deformation at the pile top is only about 1mm, and the overall deformation amplitude is at a relatively small level. Under symmetric excavation conditions, the horizontal displacement of the pile top shows no significant change, and the stress state remains stable. However, when the asymmetric excavation thickness is 3.5m, the horizontal displacement of the pile top slightly shifts towards the soil-unloading side, with the displacement amplitude ranging between 0.2–0.3 mm and the deformation influence range being limited. The study confirms that the main reason for the small heave deformation of group pile foundations is the limited amplitude of soil unloading rebound deformation. This research achievement can provide important references for the deformation prediction and design optimization of pile foundations in major projects such as high-speed railway bridges under deep excavation conditions. It is clarified that in relevant deformation calculations or numerical simulations, it is crucial to reasonably select the rebound modulus parameter based on the current stress level and unloading state of the unloaded soil, which is the key to ensuring the accuracy of calculation results.
李 剑1，秦尚林1，李世昌2，余 飞1*，戴张俊1. 深开挖下群桩基础隆起变形规律现场试验研究[J]. 岩石力学与工程学报, 2026, 45(9): 2853-2862.
LI Jian1, QIN Shanglin1, LI Shichang2, YU Fei1*, DAI Zhangjun1. Field investigation on heave behavior of pile groups induced by deep excavation. , 2026, 45(9): 2853-2862.
[1] 陈 卓. 基于列车、轨道和桥梁之间相互作用的高速铁路桥梁设计参数研究[博士学位论文][D]. 北京：中国铁道科学研究院，2020.(CHEN Zhuo. Research on high-speed railway bridge design parameters based on the interaction between trains，tracks，and bridges[Ph. D. Thesis][D]. Beijing：China Academy of Railway Sciences，2020.(in Chinese))
[2] 勾红叶，刘 畅，班新林，等. 高速铁路桥梁–轨道体系检测监测与行车安全研究进展[J]. 交通运输工程学报，2022，22(1)：1–23.(GOU Hongye，LIU Chang，BAN Xinlin，et al. Research progress on detection，monitoring，and traffic safety of high-speed railway bridge-track systems[J]. Journal of Transportation Engineering，2022，22(1)：1–23.(in Chinese))
[3] 中华人民共和国行业标准编写组. TB 10182—2017公路与市政工程下穿高速铁路技术规程[S]. 北京：中国铁道出版社，2018.(The Professional Standards Compilation Group of People?s Republic of China. TB 10182—2017 Technical Specifications for underpass of high-speed railways in highway and municipal engineering[S]. Beijing：China Railway Publishing House，2018.(in Chinese))
[4] XU K，POULOS H. 3-D elastic analysis of vertical piles subjected to “passive” loadings[J]. Computers and Geotechnics，2001，28(5)：349–375.
[5] ZHENG G，DIAO Y，NG C W W. Parametric analysis of the effects of stress relief on the performance and capacity of piles in nondilative soils[J]. Canadian Geotechnical Journal，2011，48(9)：1 354–1 363.
[6] 伍程杰，俞 峰，龚晓南，等. 开挖卸荷对既有群桩竖向承载性状的影响分析[J].岩土力学，2014，35(9)：2 602–2 608.(WU Chengjie，YU Feng，GONG Xiaonan，et al. Analysis of influence of excavation unloading on vertical bearing behavior of existing pile groups[J]. Rock and Soil Mechanics，2014，35(9)：2 602–2 608.(in Chinese))
[7] 伍程杰，龚晓南，房 凯，等. 增层开挖对既有建筑物桩基承载刚度影响分析[J]. 岩石力学与工程学报，2014，33(8)：1 526–1 535. (WU Chengjie，GONG Xiaonan，FANG Kai，et al. Analysis of influence of increasing layer excavation on bearing stiffness of existing building pile foundations[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(8)：1 526–1 535.(in Chinese))
[8] LEUNG F C ，LIM K J ，SHEN F R ，et al. Behavior of pile groups subject to excavation-induced soil movement[J]. Journal of Geotechnical and Geoenvironmental Engineering，2003，129(1)：58–65.
[9] ONG E D，LEUNG E C，CHOW K Y. Pile behavior due to excavation-induced soil movement in clay. I：Stable wall[J]. Journal of Geotechnical and Geoenvironmental Engineering，2006，132(1)：36–44.
[10] 戴自航，徐 祥. 边坡抗滑桩设计计算的三维有限元法[J]. 岩石力学与工程学报，2012，31(12)：2 572–2 578.(DAI Zihang，XU Xiang. Three-dimensional finite element method for the design and calculation of anti-slide piles on slopes[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(12)：2 572–2 578.(in Chinese))
[11] ONG D E L，LEUNG C F，CHOW Y K. Behavior of pile groups subject to excavation-induced soil movement in very soft clay[J]. Journal of Geotechnical and Geoenvironmental Engineering，2009，135(10)：1 462–1 474.
[12] 张建伟，王建华，周顺华，等. 地铁隧道上穿既有群桩基础现场试验与桩基上抬变形时空演化规律[J]. 岩土工程学报，2015，37(11)：1 981–1 989.(ZHANG Jianwei，WANG Jianhua，ZHOU Shunhua，et al. On-site tests of metro tunnels passing under existing pile group foundations and the spatiotemporal evolution law of pile uplift deformations[J]. Chinese Journal of Geotechnical Engineering，2015，37(11)：1 981–1 989.(in Chinese))
[13] 刘 波，陈福勇，何 川，等. 地铁深基坑开挖对邻近桩基变形影响的现场监测与分析[J]. 岩石力学与工程学报，2018，37(增2)：3 921–3 930.(LIU Bo，CHEN Fuyong，HE Chuan，et al. On-site monitoring and analysis of the impact of deep subway pit excavation on the deformation of adjacent pile foundations[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(Supp.2)：3 921–3 930.(in Chinese))
[14] 李镜培，张 伟，陈建峰，等. 建筑深基坑开挖诱发邻近桩基变形特性的现场监测研究[J]. 岩土工程学报，2020，42(4)：617–626.(LI Jingpei，ZHANG Wei，CHEN Jianfeng，et al. Field monitoring study on the deformation characteristics of adjacent pile foundations induced by deep foundation excavation[J]. Chinese Journal of Geotechnical Engineering，2020，42(4)：617–626.(in Chinese))
[15] 中华人民共和国行业标准编写组. JGJ 94—2021建筑桩基技术规范[S]. 北京：中国建筑工业出版社，2021.(The Professional Standards Compilation Group of People?s Republic of China. JGJ 94—2021 Technical code for building pile foundations[S]. Beijing：China Architecture & Building Press，2021.(in Chinese))
[16] 中华人民共和国行业标准编写组. JGJ 120—2012建筑基坑支护技术规程[S]. 北京：中国建筑工业出版社，2012.(The Professional Standards Compilation Group of People?s Republic of China. JGJ 120—2012 Technical specification for retaining and protection of building foundation excavations[S]. Beijing：China Architecture and Building Press，2012.(in Chinese))
[17] CHEN L，LI X，WANG Y. A constitutive model for clay considering small-strain stiffness degradation during cyclic unloading[J]. Computers and Geotechnics，2022，150：104892.
[18] WANG J，LI Z. Experimental study on nonlinear unloading-reloading behavior of soft clay under confined compression[J]. Acta Geotechnica，2021，16(5)：1 325–1 338.
[19] LIU H，ZHANG M，CHEN Y. Small-strain stiffness degradation of silty clay during excavation unloading：Laboratory and field evidence[J]. Journal of Geotechnical and Geoenvironmental Engineering，2023，149(3)：04022123.
[20] 郑 刚，程雪松，魏 纲，等. 基坑开挖卸荷条件下土体回弹模量的试验研究[J]. 岩土工程学报，2014，36(10)：1 781–1 788.(ZHENG Gang，CHENG Xuesong，WEI Gang，et al. Experimental study on the rebound modulus of soil under excavation unloading conditions[J]. Chinese Journal of Geotechnical Engineering，2014，36(10)：1 781–1 788.(in Chinese))
[21] ZHANG Q，WANG F，LIU G. Evolution of shear modulus during excavation unloading in structured clay[J]. Soils and Foundations，2020，60(4)：832–845.
[22] YAO Y P，ZHANG B，WANG L. Extension of HSS model for simulating excavation unloading with stress-path-dependent stiffness[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2022，46(8)：1 523–1 545.
[23] LI J，CHEN J，LIU B. Back-analysis of excavation-induced deformation in soft clay using unloading modulus based on field monitoring[J]. Tunnelling and Underground Space Technology，2023，133：104919.
[24] WANG R，FU D M，LI N. Unloading-reloading behavior of clay：A new perspective from energy dissipation[J]. Géotechnique，2023，73(7)：605–620.
[25] LIU Y，LI P. Small-strain stiffness degradation during excavation unloading in soft soil[J]. Canadian Geotechnical Journal，2022，59(9)：1 521–1 535.
[26] LI J，LI S，ZHANG Y，et al. Numerical method for the deformation calculation of the shallow buried tunnel caused by the excavation of overlying soil based on soil rebounding characteristics[J]. Frontiers in Earth Science，2022，10(10)：872040.
[27] 姚 亮，余 飞，李 剑，等.地表卸载下浅埋隧道变形计算方法研究[J]. 铁道标准设计，2025，69(8)：133–141.(YAO Liang，YU Fei，LI Jian，et al. Research on deformation calculation method for shallow buried tunnels under surface unloading[J]. Railway Standard Design，2025，69(8)：133–141.(in Chinese))
2026, Vol. 45 
