摘要
为探明多元荷载联合作用下软基深水超长桩承载特性及破坏模式,基于ABAQUS有限元软件,采用Green-Lagrange应变理论,建立考虑Ρ-Δ效应的软基深水超长桩有限元计算模型。在此基础上,首先开展超长桩承载特性研究,深入分析考虑与不考虑Ρ-Δ效应时桩基础承载力变化规律,桩侧摩阻力及土抗力变化规律。然后通过超长桩基础的等效塑性应变云图,进一步揭示超长桩破坏模式。结果表明:考虑Ρ-Δ效应后的桩基础竖向承载力明显减小,最大减小了91.16%,因此,在进行多元荷载联合作用下软基深水超长桩设计计算时,必须考虑Ρ-Δ效应的影响;在V-H荷载联合作用下,桩身发生挠曲变形,桩侧摩阻力和土抗力发生重分布,桩基础水平受荷一侧的桩-土发生脱开分离,靠近该侧泥面附近的桩侧摩阻力和土抗力变为0,而另一侧土体发生挤压,靠近该侧泥面附近的桩侧摩阻力和土抗力均有增大。此外,当水平荷载H较小时,超长桩基础因桩侧摩阻力不足而引起沉降破坏;而当水平荷载H较大时,超长桩发生较大塑性变形而形成“塑性铰”,最终呈现弯曲破坏模式。
In order to investigate the bearing characteristics and failure modes of super-long piles in deep water soft soil foundations under multiple combined loads,a finite element model was developed using ABAQUS software,based on Green-Lagrange strain theory and considering the Ρ-Δ effect.On this basis,the bearing characteristics of the super-long piles were first studied,with a detailed analysis of the changes in pile bearing capacity,pile-side friction,and soil resistance,both with and without considering the Ρ-Δ effect.The failure modes of the super-long piles were further revealed through equivalent plastic strain cloud diagrams.The results show that the vertical bearing capacity of the piles significantly decreases when the Ρ-Δ effect is considered,with a maximum reduction of 91.16%.Therefore,the influence of the Ρ-Δ effect must be taken into account in the design and analysis of such piles under multiple combined loads.Under the action of V-H loads,the pile undergoes deflection,and redistribution occurs in both pile-side friction and soil resistance.On the horizontally loaded side,pile-soil separation takes place,and the pile-side friction and soil resistance near the mud surface on this side reduce to zero,while compression occurs on the opposite side,leading to an increase in both pile-side friction and soil resistance.Additionally,when the horizontal load H is relatively small,the pile experiences settlement failure due to insufficient pile-side friction.However,when H is large,the pile undergoes significant plastic deformation,forming a“plastic hinge”and ultimately leading to bending failure.
作者
贺林林
谢院仕
刘洋
梁越
刘明维
HE Linlin;XIE Yuanshi;LIU Yang;LIANG Yue;LIU Mingwei(School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil and Hydraulic Engineering,Chongqing University of Science and Technology,Chongqing 401331,China)
出处
《海洋工程》
北大核心
2025年第4期174-185,共12页
The Ocean Engineering
基金
国家自然科学基金面上项目(52379097,52279124)
重庆市自然科学基金重点项目(CSTB2024NSCQ-LZX0114)
重庆市自然科学基金面上项目(CSTB2023NSCQ-MSX0873)。
关键词
多元荷载联合作用
超长桩
Ρ-Δ效应
承载特性
破坏模式
multiple combined loads
super-long piles
Ρ-Δeffect
bearing characteristics
failure mode
