ANALYSIS FOR AXIAL VIBRATION AND INTERNAL FORCES OF TOTALLY AND PARTIALLY EMBEDDED PILE GROUPS WITH FLEXIBLE CAPS
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摘要: 基于简化的完全和部分埋入群桩动力计算模型,采用有限元子结构方法,提出可以考虑承台板对群桩动力阻抗贡献的计算方法,并对均质地基和层状地基中不同桩间距条件下,承台板厚度对群桩动力阻抗的影响给予分析,详细讨论承台板惯性力的变化对群桩动力特性的影响,指出刚性承台假定的局限性。然后重点研究不同承台板厚度条件下群桩内力的分布规律。最后通过对群桩现场试验和海上风机基础动力特性的模拟,并与传统的计算方法和试验结果进行对比,说明计算方法可以更为合理、准确地预测群桩的动力响应及其变化趋势。Abstract: A simplified analytical method was developed for the axial harmonic response of totally and partially embedded pile groups in homogeneous and layered soil deposits.Based on BDWF model, finite element sub-structure method was used to setup the dynamic model of cap-pile groups which could precisely simulate cap's influence on impedance of pile groups.A comprehensive parameter study was focused the influence of the caps' height and mass density on pile groups dynamic response, and then limitation of rigid cap in practical design was presented.A solution was finally presented for the internal forces distributed on pile heads due to pile-to-pile interaction.The solution of present method was compared with that of traditional simplified method(rigid and massless cap solution) in simulating an in-site experiments of totally embedded pile groups and dynamics response of partially embedded pile groups for offshore fan foundation under harmonic load, it is demonstrated that present one can predict the pile groups dynamics response more reasonable and reliable.
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Key words:
- flexible caps /
- pile group /
- dynamic response
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