Calculation Method of Pile Foundation Settlement Displacement Based on Virtual Column Equivalent Model

doi:10.16183/j.cnki.jsjtu.2020.383

Abstract

Abstract:

According to the engineering characteristics of pile foundation in soft soil layer, a virtual column structure model was proposed, and a theoretical solution to pile foundation settlement displacement was established. Besides, the load transfer characteristics of pile foundation in soft soil layer, the bearing mode of pile foundation, and its dynamic relationship with the gradual evolution of load and environmental conditions were studied. The results show that there are friction bearing and friction with pile end bearing modes in pile foundation, and they change significantly with pile top load, construction, and environmental factors. Affected by the load transfer law, there is a 0-axis force section in the axial direction of pile foundation. The relationship between the depth and the length of pile foundation affects the type of bearing mode and displacement calculation results. The field results verify the correctness and applicability of the theoretical method.

Key words: bearing mode of pile foundation, settlement displacement, virtual column equivalent model, theoretical solution

CLC Number:

TU473

WANG Rongyong, LIU Linqi, WANG Yingyi, HUANG Xingchun. Calculation Method of Pile Foundation Settlement Displacement Based on Virtual Column Equivalent Model[J]. Journal of Shanghai Jiao Tong University, 2021, 55(9): 1126-1133.

Figures/Tables 9

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References 13

[1]	许崧, 阎长虹, 许宝田. 砂土地层中桩基受力特征试验分析[J]. 工程地质学报, 2013, 21(4):577-582.
	XU Song, YAN Changhong, XU Baotian. In-situ test and analysis on mechanical characteristics of piles in sands[J]. Journal of Engineering Geology, 2013, 21(4):577-582.
[2]	邓会元, 戴国亮, 龚维明, 等. 不同平衡堆载条件下桩基承载特性的原位试验研究[J]. 岩土力学, 2015, 36(11):3063-3070.
	DENG Huiyuan, DAI Guoliang, GONG Weiming, et al. In situ experimental study of bearing characteristics of pile foundation under different balanced surcharges[J]. Rock and Soil Mechanics, 2015, 36(11):3063-3070.
[3]	胥为捷. 软土地基桩基负摩阻力简化计算方法[J]. 水运工程, 2011(11):222-226.
	XU Weijie. Simplified calculation method for negative friction on piles in soft soil foundation[J]. Port & Waterway Engineering, 2011(11):222-226.
[4]	林心. 群桩基础流变效应分析[J]. 广东水利水电, 2013(11):41-43.
	LIN Xin. Analysis on rheological effect of pile group foundation[J]. Guangdong Water Resources and Hydropower, 2013(11):41-43.
[5]	冯胜洋. 深厚软土区段高速铁路桥梁桩基工后沉降特性研究[D]. 长沙: 中南大学, 2014.
	FENG Shengyang. Bpost-construction settlement characteristics of pile foundation for high-speed railway bridge in deep soft soil region[D]. Changsha: Central South University, 2014.
[6]	徐庆国. 京沪高速铁路群桩基础沉降变形特性研究[D]. 长沙: 中南大学, 2013.
	XU Qingguo. Theoretical study on settlement and deformation of pile groups of Beijing-Shanghai express railway[D]. Changsha: Central South University, 2013.
[7]	张乾青. 软土地基桩基受力性状和沉降特性试验与理论研究[D]. 杭州: 浙江大学, 2012.
	ZHANG Qianqing. Test and theoretical study on bearing capacity behavior and settlement of pile in soft soils[D]. Hangzhou: Zhejiang University, 2012.
[8]	TAN F Y, HU H B, LV W, et al. Study on bearing performance of mixed pile on saturated silty sand ground[J]. Japanese Geotechnical Society Special Publication, 2015, 1(6):41-46. doi: 10.3208/jgssp.CPN-19 URL
[9]	GIANNOPOULOS K, ZDRAVKOVIC L, POTTS D. A numerical study on the effects of time on the axial load capacity of piles in soft clays[M]// Numerical Methods in Geotechnical Engineering. Boca Raton, USA: CRC Press, 2000: 595-600.
[10]	ZHANG L P, SHEN Y B, WANG D D. Research on bored bearing characteristics in Xi’an[J]. MATEC Web of Conferences, 2015, 22:05025. doi: 10.1051/matecconf/20152205025 URL
[11]	肖偲, 王奎华, 王孟波. 基于桩侧虚土桩模型的桩-桩芯土竖向动力响应[J]. 浙江大学学报(工学版), 2020, 54(8):1593-1603.
	XIAO Si, WANG Kuihua, WANG Mengbo. Vertical dynamic response of pile-soil plug based on surrounding fictitious soil pile model[J]. Journal of Zhejiang University (Engineering Science), 2020, 54(8):1593-1603.
[12]	辛冬冬, 张乐文, 宿传玺. 基于虚土桩模型的层状地基群桩沉降研究[J]. 岩土力学, 2017, 38(8):2368-2376.
	XIN Dongdong, ZHANG Lewen, SU Chuanxi. Settlement research of pile groups in layered soils based on virtual soil-pile model[J]. Rock and Soil Mechanics, 2017, 38(8):2368-2376.
[13]	王奎华, 吕述晖, 吴文兵, 等. 层状地基中基于虚土桩模型的单桩沉降计算方法[J]. 工程力学, 2013, 30(7):75-83.
	WANG Kuihua, LÜ Shuhui, WU Wenbing, et al. A new calculation method for the settlement of single pile based on virtual soil-pile model in layered soils[J]. Engineering Mechanics, 2013, 30(7):75-83.

土体		桩基
参数	取值	参数	取值
ϕ/(°)	15	D/mm	900
C/kPa	30	H/m	76.6
μ	0.4	A/m²	0.63617
γ/(kN·m^-3)	1.81	E/GPa	30
E_s/MPa	10.0

土层名称	平均厚度/m	ϕ/(°)	E/MPa	C/kPa	γ/ (kN·m^-3)
黏土	2.00	17.50	3.00	34.00	19.1
淤泥	1.95	17.90	1.60	22.00	17.0
细砂	3.75	16.95	8.00	10.50	18.0
淤泥	15.70	10.25	2.00	20.35	17.1
细砂	4.20	16.95	10.00	10.50	18.0
淤泥质黏土	9.75	11.40	2.50	80.00	17.5
细砂	4.90	16.95	12.00	10.50	18.0
黏土	5.50	16.40	6.50	43.00	19.6
黏土	10.05	12.45	4.00	64.50	18.4
粉质黏土	14.45	17.35	6.00	41.50	19.1
卵石	12.10	20.00	18.50	0	18.5
按地层厚度加权平均		18	10	40	18.1

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