【作者】 佟保林；

【导师】 岳前进；

【作者基本信息】 大连理工大学 ， 固体力学， 2008， 硕士

【摘要】 海冰是渤海近海结构物的控制环境荷载。在目前的抗冰平台设计中通常只考虑了在极值静冰力下的最大承载力;而交变冰力作用下对平台结构与上部设施产生的影响尚没有充分考虑。基于现场原型结构的监测显示,海冰在与平台作用时产生明显的周期性荷载,可以激起平台较大的加速度响应。特别是对生产天然气的平台,上部布置错综复杂的天然气管线,这些管线在长期的冰振作用下,可能使管线的连接部件发生松动,轻则引起泄露,重则会由断裂而引起爆炸,给平台的安全生产带来不同程度的经济损失。本文通过现场检测、监测和数值模拟等手段对海洋平台上部管线系统的失效问题进行研究,给出该失效模式的主要判据,并且指出该种失效模式是无法避免的,应提高管线的抗振设防等级。本文还对管线系统在冰激振动下的动态响应问题做了分析,明确了冰激振动对管线的影响剧烈,应在设计中考虑动冰力对管线的影响。最后通过算例分析了交变动冰荷载对现役平台JZ20-2和即将投产于渤海JZ21-1WHPA油气矿平台上部管线系统的影响,提出了通过调整管线支撑来减小振动的措施,完善了平台管线系统的设计,为今后抗冰平台管线的设计提供了依据。更多还原

【Abstract】 The sea ice is the dominant environmental force for the offshore structures in the Bohai Bay. In the present design the maximum bearing capacity under the limited ice load is considered, but the effect of structures and facilities induced by dynamic ice force are neglected. Based on full-scale tests of the offshore structures in Bohai Bay, it is found that sea ice can induce the periodic load and make the offshore jacket structures vibrate with major acceleration. For the jacket platforms used to produce natural gas, there are complicated natural gas pipelines. Ice-induced vibrations could lead to the associated accidents of pipelines on the platform, such as fatigue fracture of pipe and looseness of flanges, which makes all kinds of economy losses for the platform.In this paper, the failure problem of the pipeline systems on the platform is researched by spot test, monitor, and numerical simulation. It is pointed out the major criterion of the failure mode and this kind of failure mode is inevitable. In order to improve the condition the pipeline ice-resistant rank should be enhanced. In this paper, the dynamic response of pipeline systems under the ice-induced vibration is analyzed, and it is found that the ice-induced vibration effects pipeline acutely. So it is necessary to consider the effects on pipeline induced by dynamic force during the design. Finally giving an example, for the pipeline systems of the JZ20-2 platform which is service and the ones of the JZ21-1WHPA platform which is about to go into production in Bohai Bay, author analyzes the effects on it induced by dynamic ice force, points out the methods of reducing vibration by improving braces, and develops the pipeline systems design on offshore platforms, which will be helpful to pipeline systems on the new ice-resistant platforms.更多还原