Abstract This paper presents an analytical approach for predicting the nonlinear load-displacement behaviour of pile groups consisting of displacement piles in normally consolidated and lightly overconsolidated clayey soils. The effects of squeezing and remolding on the soil around the piles caused by pile installation are reflected by the soil strength and shear modulus. The nonlinear load-displacement behaviour at the pile-soil interface is modeled by the load-transfer method with exponential load-transfer functions and the pile-pile interaction effects are reflected by the shear displacement method. A hybrid analytical method, incorporating the developed soil parameters and combining the load transfer method and the shear displacement method, is proposed for the problem considered. Four sets of centrifuge model tests, involving pile groups with different pile diameters, pile lengths and pile spacings, were conducted to verify the proposed analytical framework. The validity of the proposed method, the significance of the installation effects as well as the nonlinear behaviour of the pile groups are demonstrated by comparing the load-displacement curves from the centrifuge model tests with those from the proposed method and other relevant methods. Parametric studies are conducted to investigate the pile diameter, pile length, pile spacing and pile number on the stiffness efficiency of pile groups. The results indicate that increasing the pile diameter and length can effectively improve the stiffness efficiency and the load carrying behaviour of displacement pile groups.

中文翻译：

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考虑安装效应的粘土桩群非线性荷载位移行为分析

摘要 本文提出了一种分析方法，用于预测由正常固结和轻度超固结粘土中的位移桩组成的桩群的非线性荷载-位移行为。桩基安装对桩周土体产生的挤压和重塑的影响通过土体强度和剪切模量来体现。桩-土界面的非线性荷载-位移行为通过具有指数荷载-传递函数的荷载-传递方法建模，桩-桩相互作用效应由剪切位移方法反映。针对所考虑的问题，提出了一种结合已开发的土壤参数并结合载荷传递方法和剪切位移方法的混合分析方法。四组离心机模型试验，涉及具有不同桩径、桩长和桩间距的桩组，以验证所提出的分析框架。通过将离心机模型试验的荷载-位移曲线与所提出的方法和其他相关方法的荷载-位移曲线进行比较，证明了所提出方法的有效性、安装效应的显着性以及桩组的非线性行为。进行参数研究以研究桩径、桩长、桩间距和桩数对桩群刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。进行了验证拟议的分析框架。通过将离心机模型试验的荷载-位移曲线与所提出的方法和其他相关方法的荷载-位移曲线进行比较，证明了所提出方法的有效性、安装效应的显着性以及桩组的非线性行为。进行参数研究以研究桩径、桩长、桩间距和桩数对桩群刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。进行了验证拟议的分析框架。通过将离心机模型试验的荷载-位移曲线与所提出的方法和其他相关方法的荷载-位移曲线进行比较，证明了所提出方法的有效性、安装效应的显着性以及桩组的非线性行为。进行参数研究以研究桩径、桩长、桩间距和桩数对桩群刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。通过将离心机模型试验的荷载-位移曲线与所提出的方法和其他相关方法的荷载-位移曲线进行比较，证明了安装效应的重要性以及桩组的非线性行为。进行参数研究以研究桩径、桩长、桩间距和桩数对桩群刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。通过将离心机模型试验的荷载-位移曲线与所提出的方法和其他相关方法的荷载-位移曲线进行比较，证明了安装效应的重要性以及桩组的非线性行为。进行参数研究以研究桩径、桩长、桩间距和桩数对桩群刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。桩间距和桩数对群桩刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。桩间距和桩数对群桩刚度效率的影响。结果表明，增加桩径和桩长可以有效提高位移桩群的刚度效率和承载性能。