【作者】 李景阳；

【导师】 李广雪；

【作者基本信息】 中国海洋大学 ， 海洋地质， 2009， 硕士

【摘要】 21世纪是海洋的世纪。近年来,我国加快了海洋油气资源的开发和利用,海底管道的铺设量逐年增加。在从近岸平台向陆地的油气输送中,管道输送仍然是目前最重要的运输方式之一。然而,海底管道所处的海洋环境复杂,管道周围底床在波浪、潮流等水动力的作用下极易产生冲刷,造成管道悬跨。悬跨段的管道没有了底床的支持力和摩擦力,在波浪、潮流力的作用下很容易发生振动,对管道的安全稳定性造成极大的破坏。本文基于大型物理模型试验,通过水槽中进行的管道试验所观察到的现象以及采集的数据进行整理分析,对管道的受力振动问题进行了系统的研究。本文介绍了目前国内外对于海底管道底床冲刷,受力振动问题的研究现状,并提出了本文的研究特点。对物理模型试验的试验条件,试验内容等进行了详细的描述。通过对试验中底床变化的细致观察,将海底管道周围底床冲刷和沙波形成过程进行详细的说明,总结出一定的规律。本文针对我国海底管道大都铺设于细颗粒物海床的特点,主要对粉土海床上海底管道的受力情况进行分析。对比不同组次的试验,总结出不同波浪要素,不同埋置深度海底管道的受力特征,并分析了流的作用对管道受力的影响,弥补了国内外关于波流联合作用研究的不足。本文通过中砂、极细砂海床与粉土海床的受力进行对比,分析底床对海底管道受力的影响。在此基础上对粉土海床平铺海底管道在波流联合作用下的受力过程进行详细的分析。此外,本文还试探性的引入了“剩余力”的概念,对单个波浪过程的作用进行分析,以便研究管道的振动趋势。最后,本文介绍了管道涡流振动的机理,并结合东方1-1管道的测量资料和所在研究区的概况,分析了有无台风两种情况下,海底管道的振动疲劳问题,对该区域的管道施工维护提供参考。更多还原

【Abstract】 The twenty-first century is ocean century. In recent years, the exploitation of marine oil and gas has developed very fast in our nation. Thus, submarine pipelines have been increasing every year. Pipelines transportation is still one of the important transportation modes, delivering oil and gas from offshore platform to land. However, in complex marine environment, bed around pipelines arouse scour easily under the effect of the hydrodynamic terms, such as wave or tidal current, then result in span. The spanning pipelines will lose the supportive force and friction. When the wave or tidal current force acted on, the pipelines will vibrate. This will break the safety and stability of the pipelines extremely.The paper based on physical model tests, studied the force-induced vibration systematically through the phenomenon observed and the data collected in the tests.Research status at home and abroad presently is introduced, including scour of the bed and force-induced vibration, then the characteristic of the paper is brought forward. The conditions and content of the physical model tests are described detailedly. The courses of the scour aroud the pipeline and the formation of sand waves are explained in detail through the close observation of the change in bed, and certain rules are summarized too.The force acted on submarine pipelines in silty bed is analyzed mainly, because the pipelines are generally layed on fine sediments in our country. Through the contrast of different trials, the characteristic of the force influenced by the differences of the wave elements and the burial depth is summarized. Then the influence of the force under current is also analyzed, making up for the lack of the research at home and abroad about the effect under both wave and current.The influence of the force acted on pipelines on different kinds of seabed is studied by the contrast of the three sorts of beds- medium sand, fine sand and silt seabed. The process of the force acted on the submarine pipelines under both wave and current in silty bed is analyzed concretely on above basis. In addition, a new concept- residual force is introduced tentatively, which is used to study the effect in single wave period, in order to explain the development tendency of the pipelines vibration.At last, the mechanism of vortex-induced vibration is expounded. And the vibration fatigue of the pipelines is discussed by applying the survey data of DF1-1 GAS LINE and the general situation of the research area, under typhoon or not. This research will help the installation and the maintenance of the pipelines in the area.更多还原