波流作用下钢管桩的动力响应研究

发布时间：2018-05-10 16:39

本文选题：钢管桩 + 改进的JONSWAP谱　；参考：《大连理工大学》2014年硕士论文

【摘要】：近五十年以来,钢管桩渐渐成为基础工程中的重要桩型。钢管桩广泛的应用于深水码头、施工栈桥和海洋平台。钢管桩竖向和水平向承载力都比较大,常常作为高、大、重结构以及受水平力作用的结构的基础桩。随着海洋开发、海上采油工程事业的蓬勃发展,对钢管桩动力响应特性的研究越来越得到人们的重视。在港口工程和海洋工程中,钢管桩施工就位后就会受到波浪和水流荷载的作用,钢管桩在波流荷载下的动力响应对结构安全有重要影响；尤其是在上部结构没有完成时,桩只能靠自身结构承受这些荷载。在施工状态下,钢管桩处于单桩形态,此时更偏于危险,因而分析此状态下受波流荷载作用的钢管桩的变形和应力,就显得更为重要。本文首先基于有限元法,建立了计算结构动力响应的数值模型,采用八结点六面体划分网格,结合改进平方根算法,通过求解以结点位移为未知量的结点平衡方程,得到结构的结点位移和应力。并且采用Newmark方法对结构进行动力响应分析,得到在外荷载作用下结构的变形和应力在时域内的时程变化。然后,采用改进的JONSWAP谱模拟了不规则波浪谱,通过与靶谱吻合度的对比分析,得到了最佳模拟效果的模拟参数。进而根据Airy波理论求得了任意时刻水质点的速度和加速度,从而通过莫里森公式计算了随时间变化的波流荷载。最后采用此数值模型,对处于施工状态的栈桥钢管桩,进行了波流荷载作用下的动力响应分析,得到了钢管桩变形和内力的时程变化,而且钢管桩受到周期性冲击。因而对时程变化曲线作了FFT变换,通过频谱分析,得到了该周期性冲击主要是由波浪荷载引起的共振所导致的。
[Abstract]:In the past 50 years, steel pipe pile has gradually become an important pile type in foundation engineering. Steel pipe piles are widely used in deep water wharf, construction trestle and offshore platform. The vertical and horizontal bearing capacity of steel pipe pile is relatively large, which is often used as foundation pile with high, large and heavy structure and structure subjected to horizontal force. With the development of marine exploitation and offshore oil recovery engineering, more and more attention has been paid to the dynamic response of steel pipe piles. In port engineering and offshore engineering, steel pipe piles will be subjected to wave and current loads when they are in place. The dynamic response of steel pipe piles under wave-current loads has an important impact on the safety of the structure, especially when the superstructure is not completed. The pile can only bear these loads by its own structure. Under the condition of construction, the steel pipe pile is in the form of a single pile, which is more dangerous. Therefore, it is more important to analyze the deformation and stress of the steel pipe pile under the action of wave and current load. In this paper, based on the finite element method, a numerical model is established to calculate the dynamic response of the structure. The eight-node hexahedron is used to mesh and the improved square root algorithm is used to solve the nodal equilibrium equation which takes the nodal displacement as the unknown quantity. The node displacement and stress of the structure are obtained. The Newmark method is used to analyze the dynamic response of the structure, and the time-history changes of the deformation and stress of the structure under the external load are obtained. Then, the irregular wave spectrum is simulated by using the improved JONSWAP spectrum, and the simulation parameters of the best simulation effect are obtained by comparing and analyzing the coincidence between the wave spectrum and the target spectrum. According to the Airy wave theory, the velocity and acceleration of water quality point at any time are obtained, and the wave and current loads varying with time are calculated by Morrison formula. Finally, the dynamic response of the steel pipe pile under wave-current load is analyzed by using this numerical model, and the time history variation of the deformation and internal force of the steel pipe pile is obtained, and the steel pipe pile is subjected to periodic impact. In this paper, the time-history curve is transformed by FFT transform, and the frequency spectrum analysis shows that the periodic shock is mainly caused by the resonance caused by wave load.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1;TV139.26

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