桥墩遭受船舶撞击下的动力响应及其防撞结构研究

发布时间：2018-03-24 20:39

本文选题：船舶撞击　切入点：分离式模型　出处：《天津大学》2014年硕士论文

【摘要】：伴随着交通运输事业的迅速发展,船桥相撞的事故屡屡发生,已受到越来越多的关注和研究。本文基于多种力学理论和数值模拟技术,采用LS-DYNA软件,研究了桥墩遭受船舶撞击时的动力响应及其变化规律,并讨论了各撞击参数对桥墩动力响应的影响;总结了前人对防撞结构的设计思路,并设计了桥墩防撞结构;通过研究船舶撞击桥墩防撞结构时桥墩和船舶的动力响应,对比分析了防撞结构的有效性,并讨论了各碰撞参数对桥墩和船舶动力响应的影响。本文的主要研究工作和研究成果如下:(1)借助ANSYS/LS-DYNA建立了桥墩分离式附加质量模型和船舶模型,并模拟了船舶撞击桥墩的全过程。通过分析碰撞过程中桥墩和船舶的动力响应发现:墩柱的位移会滞后于承台;桩基在与承台连接处和土体顶面处会出现高应力区。(2)对水位、桩基纵筋直径和桩基直径进行了参数分析,对比了不同工况下桥墩和船舶的动力响应,得到以下结论:随着水位的增加,桥墩的位移、桩基顶部截面的剪力和弯矩以及船艏的撞深也会随之增加;随着桩基纵筋直径和桩径地增加,桥墩的位移会显著减少,桥墩的变形回弹速度和船艏的撞深会显著增加。(3)设计了本文中的桥墩防撞结构,并比较了船舶撞击桥墩防撞结构时与直接撞击桥墩时,桥墩和船舶的动力响应。分析发现:防撞结构能够在撞击中起到很好的缓冲作用,能够显著的减少传递给桥墩的碰撞力;添加防撞结构后,桥墩和船舶在撞击时的动力响应会显著降低。(4)讨论了水位、碰撞位置、防撞结构外钢围强度和橡胶硬度对撞击结果的影响,得到以下结论:碰撞力峰值和桥墩动力响应会随着水位的增加而增加,船艏撞深差别较小;船舶撞击防撞结构斜面时,桥墩和船舶的动力响应较正碰时大幅度减小;随着防撞结构外钢围强度的增加,桥墩和船舶的动力响应都会随之增大,船艏撞深受外钢围强度的影响更显著;橡胶的硬度过高和过低时,桥墩和船舶的动力响应都会较大,说明橡胶硬度应合理选取。
[Abstract]:With the rapid development of traffic and transportation, the accidents of collision of ships and bridges occur frequently and have been paid more and more attention and research. Based on various mechanics theories and numerical simulation techniques, this paper adopts LS-DYNA software. In this paper, the dynamic response of pier subjected to ship impact and its variation law are studied, and the influence of impact parameters on the dynamic response of pier is discussed, and the design ideas of anti-collision structure are summarized, and the anti-collision structure of pier is designed. By studying the dynamic response of the pier and the ship when the ship impacts on the bridge pier, the effectiveness of the anti-collision structure is compared and analyzed. The influence of collision parameters on the dynamic response of bridge piers and ships is discussed. The main work and results of this paper are as follows: 1) with the help of ANSYS/LS-DYNA, the separated additional mass model and ship model of bridge pier are established. Through the analysis of the dynamic response of the pier and the ship during the collision, it is found that the displacement of the pier column will lag behind that of the cap, and the high stress zone of pile foundation will appear at the joint with the cap and at the top of the soil mass) to the water level, and the analysis of the dynamic response of the pier and the ship during the collision process shows that the displacement of the pier column will lag behind that of the pile cap. The dynamic responses of piers and ships under different working conditions are compared. The conclusions are as follows: with the increase of water level, the displacement of piers is increased. The shear force and bending moment of the top section of the pile foundation and the collision depth of the bow will also increase, and the displacement of the pier will be significantly reduced with the increase of the diameter of the longitudinal reinforcement and the diameter of the pile. The deformed springback velocity of pier and the collision depth of bow will be significantly increased.) the anti-collision structure of pier in this paper is designed, and the collision resistant structure of the bridge pier is compared when the ship hits the pier anti-collision structure with the direct impact on the pier. The dynamic response of bridge piers and ships. It is found that the anti-collision structure can play a good buffer role in the impact, can significantly reduce the impact force transferred to the pier, after adding the anti-collision structure, The effects of water level, impact location, external steel girth strength and rubber hardness on the impact results are discussed. The conclusions are as follows: the peak value of collision force and the dynamic response of pier will increase with the increase of water level, and the difference of bow collision depth will be small, and the dynamic response of pier and ship will decrease greatly when the ship impacts on the oblique deck of anti-collision structure. With the increase of external steel girth strength of anti-collision structure, the dynamic response of bridge piers and ships will increase, and the impact of bow collision on steel girth strength will be more obvious, and when rubber hardness is too high and too low, the dynamic response of piers and ships will be larger. It shows that rubber hardness should be reasonably selected.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U443.26

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