考虑土体非线性的部分埋入群桩竖向振动分析

Analysis of Dynamic Response of Partially Embedded Pile Group with a Consideration of Soil Nonlinearities in Vertical Vibration

摘要:

在桩基振动问题中,桩侧土往往表现出显著的非线性特性,土体动模量和阻尼的大小与桩身位移相关.目前的分析方法一般只采取恒定的土性参数,忽略了非线性的影响.基于部分埋入群桩竖向振动的研究成果,以桩身位移与土性参数之间的相互关系为依据,运用迭代方法考虑了土体非线性对部分埋入群桩振动的影响,分析了迭代收敛的条件,并通过算例分析了非线性的影响程度,观察了它与荷载大小的关系.最后,将该方法应用于分析某海上风力发电机组群桩基础的振动特性,得到其阻抗值及位移响应曲线.

Abstract:

As for the problem of pile vibration,the properties of the soils surrounding the pile are always nonlinear,that is,the dynamic module and damping of the soil are associated with the displacements of the pile shaft.In present methods,only constant properties of the soil are adopted,but the nonlinearities are neglected.Based on the achievements of the research on vertical dynamic response of partially embedded pile groups,nonlinearities are taken into consideration through the method of calculating pile shaft displacements and soil properties by iterative method according to the interrelationships between them,and iterative convergence is also analyzed.Taking 3×3 pile group for example,the effect of soil nonlinearities are analyzed,and the relationships between it and the load value are observed.Finally this method is used to predict the dynamic response of the pile group foundation of an offshore wind turbine generator,gaining its impedances and displacement response curves.