水流荷载作用下高桩码头排架结构性状及承载力研究

发布时间：2018-07-18 21:01

【摘要】：高桩码头是软土地基码头的主要结构型式。水流不仅对高桩码头排架产生静动荷载作用,而且还可能产生结构涡激振动。研究水流荷载作用下高桩码头的稳定性与水平承载力有重要意义。本文以高桩码头排架结构为研究对象,采用理论分析与数值模拟相结合的方法,研究基桩和排架在水流作用下的工作性状和承载特性；采用振动理论,研究横梁与桩的不同连接方式、桩与土的不同嵌固方式对码头基桩自振频率的影响,分析涡激振动对排架结构的动力效应。(1)多向水流荷载作用下桩土工作性状研究表明,双弹簧法高估了土的水平抗力,不完全适合于分析多向受荷桩,推荐采用三维地基梁-弹簧模型。(2)排架结构群桩效应与五基桩模型的对比分析表明,横梁对排架基桩的桩顶水平变位有约束作用,横梁的约束降低了基桩的桩身变形程度,减小了基桩的泥面位移,减弱了基桩间的群桩效应。(3)水流荷载作用下排架结构承载力研究表明,横梁对基桩桩顶的约束作用提高了排架结构整体的抗弯刚度,增大了基桩的水平承载能力,排架结构稳定性远好于基桩结构。(4)高桩码头基桩和排架结构的振动分析表明,桩底固定、桩顶自由时水中基桩的自振频率为1.54Hz,横梁与桩的不同连接方式、桩与土的不同嵌固方式不改变水中基桩的自振频率。水流对基桩和排架的动力效应与漩涡周期和结构自振频率密切相关,当漩涡产生周期为1.9s时,水流对基桩的动力系数为1.13,动力效应较为明显,对排架一阶振型的动力系数达到71.04,排架共振效应明显。
[Abstract]:High pile wharf is the main structure type of soft foundation wharf. The flow of water not only produces static and dynamic load on the bent frame of high pile wharf, but also may produce vortex-induced vibration. It is of great significance to study the stability and horizontal bearing capacity of high-pile wharf under the action of water flow. This paper takes the bent structure of high pile wharf as the research object, uses the method of theoretical analysis and numerical simulation to study the working behavior and bearing characteristics of foundation pile and bent frame under the action of water flow, and adopts the vibration theory, In this paper, the influence of different connecting modes of beam and pile on the natural vibration frequency of foundation pile of wharf is studied, and the dynamic effect of vortex-induced vibration on the structure of bent frame is analyzed. (1) the behavior of pile-soil under multi-direction flow load is studied. The double spring method overestimates the horizontal resistance of soil and is not fully suitable for the analysis of multi-direction loaded piles. Three-dimensional beam-spring model of foundation is recommended. (2) the comparison between pile group effect of bent frame structure and five-foundation pile model shows that, The horizontal displacement of the pile top of the bent pile is restrained by the beam. The constraint of the beam reduces the deformation degree of the pile body and the mud surface displacement of the foundation pile. (3) the research on the bearing capacity of bent structure under the action of water flow shows that the restraint action of beam on the top of pile increases the flexural stiffness of the whole bent structure and the horizontal bearing capacity of foundation pile. The stability of bent structure is much better than that of foundation pile structure. (4) the vibration analysis of foundation pile and bent structure of high pile wharf shows that when the pile bottom is fixed and the pile top is free, the natural vibration frequency of the foundation pile in water is 1.54 Hz. The natural vibration frequency of the foundation pile in water is not changed by the different fixing ways of pile and soil. The dynamic effect of water on pile and frame is closely related to the period of vortex and the natural frequency of structure. When the period of vortex is 1.9 s, the dynamic coefficient of flow to pile is 1.13, and the dynamic effect is obvious. The dynamic coefficient of the first order mode is 71.04, and the resonance effect is obvious.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U656.113

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