Research on overall stability of steel pipe pile group with lateral displacement under dynamic top-down excavation

被引：0
|
作者：
Wang Z. [1 ,2 ,3 ]
Yang X. [2 ]
Zhao Y. [1 ,3 ,4 ]
Zhang R. [1 ]
机构：
[1] Department of Civil Engineering, Zhejiang University City College, Hangzhou
[2] Zhejiang Province Institute of Architectural Design and Research, Hangzhou
[3] Key Laboratory of Space Structures of Zhejiang Province, Zhejiang University, Hangzhou
[4] Space Structures Research Center, Zhejiang University, Hangzhou
来源：
Jianzhu Jiegou Xuebao/Journal of Building Structures | 2021年 / 42卷
关键词：
Adverse effect; Calculation length coefficient; Dynamic excavation; Initial geometric imperfection; Lateral restraint; Steel pipe pile group under static pressure;
D O I：
10.14006/j.jzjgxb.2021.S1.0056
中图分类号：
学科分类号：
摘要：
The bearing capacity of steel pipe pile group under static pressure is very important to the safety of existing building when the basement is added by reverse construction. In order to obtain the overall stability performance of steel pipe pile group with lateral displacement under top-down excavation, a nonlinear calculation method for the stability bearing capacity of steel pipe pile group was firstly proposed considering initial geometric imperfection. Secondly, based on the linear eigenvalue analysis, the influence of lateral constraints such as the horizontal resistance of soil on two plans (pile top anchored on existing foundation (plan 1) or transfer platform (plan 2)) was discussed in depth. The stability bearing capacity and the calculation length were also obtained. Then, through introducing the uniform mode and lateral displacement imperfection of foundation pit, the nonlinear extreme point analysis was applied to obtain the adverse effect of initial imperfection, and the amplification factor of calculation length was proposed to obtain the modified nonlinear ultimate stability bearing capacity. Finally, taking the steel pipe pile group and the overall model as examples, the lateral stiffness difference of the two plans and the overall lateral displacement under actual wind loading were analyzed. The results show that the stability bearing capacity of plan 2 for steel pipe pile group under top-down excavation is significantly improved compared with that of plan 1, and the critical load ratio is about 3.30-3.40 for different horizontal resistance of soil. The nonlinear stability loading factor considering initial imperfection is smaller than that of linear analysis, and the bearing capacity decreases with the amplitude of the imperfection. In engineering design, it is suggested to enlarge the calculation length to 1.15 times according to the envelope method. Under the horizontal wind loading, the maximum overall lateral displacement of the two plans for the top of steel pipe pile group is about 50 mm, and the adverse effect of the lateral displacement imperfection on the nonlinear bearing capacity should not be ignored. © 2021, Editorial Office of Journal of Building Structures. All right reserved.
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页码：492 / 504
页数：12
相关论文
共 25 条
  • [1] XU Zhijun, ZHAO Xihong, The reverse design and construction method, pp. 197-289, (2002)
  • [2] XU Kaijun, YANG Hongpo, WU Zhengguang, Application of partial top-down construction of excavations under complex environment, Chinese Journal of Geotechnical Engineering, 34, pp. 649-653, (2012)
  • [3] SHENG Chunling, LI Renmin, WANG Shouchao, Et al., Vertical adjustment method for soldier piles in top-down projects, Chinese Journal of Geotechnical Engineering, 34, pp. 595-597, (2012)
  • [4] YANG Xuelin, WANG Zhen, Bearing capacity and stability of vertical column under dynamic construction, Rock and Soil Mechanics, 37, pp. 53-59, (2016)
  • [5] JIA Qiang, YING Huiqing, ZHANG Xin, Construction of basement in existing buildings by static bolt-pile, Rock and Soil Mechanics, 30, 7, pp. 2053-2057, (2009)
  • [6] WU Jiangbin, WANG Xiangjun, SONG Qingjun, Application of foundation reinforcement by anchor-jacked piles under low clearance, Chinese Journal of Geotechnical Engineering, 39, pp. 162-165, (2017)
  • [7] YANG Xuelin, ZHU Wenwei, ZHOU Pinghuai, Design key technique of additional basement constructed by top-down excavation below the existing high-rise building, Chinese Journal of Rock Mechanics and Engineering, 37, pp. 3775-3786, (2018)
  • [8] GONG Xiaonan, WU Chengjie, YU Feng, Et al., Shaft resistance loss of piles due to excavation beneath existing basements, Chinese Journal of Geotechnical Engineering, 35, 11, pp. 1957-1964, (2013)
  • [9] DU Jianmin, YUAN Yingshu, XIANG Wei, Prediction model of antipunching shear bearing capacity for frame columns underpin system, Journal of China University of Mining & Technology, 36, 1, pp. 60-64, (2007)
  • [10] LI Dechao, QIAN Jiangu, WU Shiming, Et al., Numerical analysis of deformation behaviors of underpinning piles during excavation, Chinese Journal of Geotechnical Engineering, 34, pp. 238-242, (2012)
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