海洋环境中桩—承台复合基础波浪荷载研究

发布时间：2019-04-25 08:51

【摘要】：跨海桥梁一般修建在河口入海口及海岸线各水域,这些地方环境比较恶劣,为桥梁基础的施工及后期管养均带来了巨大的挑战。跨海桥梁大多采用大跨结构、深水基础,是典型的深水桥梁。与内陆桥梁相比,深水桥梁的下部结构和基础除了承受自重荷载、交通荷载以外,还遭受波浪、水流等海洋动力荷载的侵袭。鉴于桩基具有抗震性能好、承载力高、沉降小的优势,目前所建的深水跨海桥梁基础形式多采用桩基-承台复合基础,因此本文主要针对桩基-承台复合基础的波浪荷载展开研究。本文通过求解RANS方程和κ-ε湍流模型,基于CFD软件FLOW-3D建立了波浪与桩-承台复合基础相互作用的三维数值模型,并基于此模型研究了桩-承台复合基础所受波浪荷载。主要研究内容包括:(1)基于FLOW3D软件分别建立二维数值波浪水槽与波浪-结构物相互作用的数值模型,通过与解析结果及以往实验结果进行对比,验证了本文数值模型的合理性。在确定本文水槽模型的准确性后,进一步建立了波浪与桩-承台复合基础相互作用的三维数值模型。(2)研究了承台淹没深度对复合基础周围流场特征及所受波浪荷载的影响,并进一步探讨了波浪参数对复合基础波浪荷载随承台淹没深度变化规律的影响。(3)研究了波浪入射角对复合基础周围流场特征及所受波浪荷载的影响,并进一步探讨了波浪参数对复合基础波浪荷载随波浪入射角变化规律的影响。(4)以平潭海峡公铁两用大桥某桥梁基础为工程对象,研究了承台淹没深度及波浪入射角对复合基础波浪荷载影响,从而进一步验证了本文第三、四章得到的相关结论,最后同时考虑承台淹没深度及波浪入射角,给出了平潭海峡公铁两用大桥桥梁基础波浪荷载随承台淹没深度及波浪入射角的变化曲线。
[Abstract]:Generally, cross-sea bridges are built in estuaries and coastal waters. The environment in these areas is rather bad, which brings great challenges to the construction of the bridge foundation and the later maintenance of the bridge. Most of the cross-sea bridges use long-span structure, deep-water foundation, is a typical deep-water bridge. Compared with inland bridge, the substructure and foundation of deep-water bridge not only bear self-weight load, traffic load, but also suffer from ocean dynamic loads such as wave, current and so on. Because the pile foundation has the advantages of good seismic performance, high bearing capacity and small settlement, the pile foundation-cap composite foundation is often used in the deep-water bridge foundation form at present. Therefore, the wave load of pile-cap composite foundation is studied in this paper. In this paper, by solving RANS equation and 魏-蔚 turbulence model, a three-dimensional numerical model of wave-pile-cap composite foundation interaction is established based on CFD software FLOW-3D. Based on this model, the wave load on pile-cap composite foundation is studied. The main contents are as follows: (1) the two-dimensional numerical model of wave-structure interaction is established based on FLOW3D software, and the numerical model is compared with the analytical results and the previous experimental results. The rationality of the numerical model is verified. After determining the accuracy of this model, A three-dimensional numerical model of the interaction between wave and pile-cap composite foundation is established. (2) the influence of the submerged depth of the cap on the characteristics of the surrounding flow field and the wave load on the composite foundation is studied. The influence of wave parameters on the variation of wave load with cap depth is further discussed. (3) the influence of wave incident angle on the flow field around the composite foundation and the wave load on the composite foundation are studied. Furthermore, the influence of wave parameters on the variation of wave load with wave incident angle is discussed. (4) A bridge foundation of Pingtan Straits Highway and Railway Bridge is taken as the engineering object, and the influence of wave parameters on the wave load of composite foundation with wave incident angle is also discussed. The influence of cap submergence depth and wave incident angle on wave load of composite foundation is studied, and the relevant conclusions obtained in chapters 3 and 4 of this paper are further verified. Finally, the submergence depth and wave incident angle of cap are considered at the same time. The variation curves of wave load on the foundation of Pingtan Straits Bridge with submerged depth of cap and wave incident angle are given.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U443.15

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