不同覆盖层对海底管道受落锚冲击防护有效性的试验研究

海底管道是海上油气工程的重要基础设施。随着港口运输规模的不断扩大和海洋油气工程的快速发展,港口航道区域与海底管道登陆段发生重叠情况不可避免。第三方活动造成的坠落物撞击(如船舶落锚),会威胁航道下方埋设的海底管道的结构安全。为了寻求合理的防护措施,保证海底管道的安全运行,有必要对落锚引起的管道动态响应进行研究。文章采用物理模型实验的方法,对管道上方覆盖的纯块石层、混凝土块层+块石层、混凝土块层+橡胶垫+块石层、柔性防护垫层+块石层等不同防护形式的有效性进行了对比研究。利用光纤布拉格光栅(FBG)传感器实时测量管道表面的动态应变响应,分析其沿管道的轴向变化以及极值分布。通过模型试验确定了相对有效的覆盖层形式及设计厚度,为海底管道的设计和维护提供了重要依据。

Experimental study on performance of different cover layers for protecting a submarine pipeline from a dropped anchor

Submarine pipelines are key infrastructures in offshore oil and gas engineering.With the rapid developments of the port engineering and offshore oil and gas engineering,overlap may occur between the harbor channel area and the landfall part of submarine pipelines.There is an occurrence that a buried submarine pipeline below a channel is damaged by the collision of falling objects from the third party activities,e.g.,a falling anchor from a ship.In order to seek reasonable protection measures to ensure the safe operation of the pipeline,it is necessary to analyze the dynamic response of the pipeline caused by the dropped objects.In this paper,different protective measures on the pipeline,including pure rock layer,concrete mattress+rock layer,concrete mattress+rock layer+rubber pad and compound flexible pad+rock layer,were physically modelled to study the impact effect of a dropped anchor on the pipelines.The dynamic responses of the pipeline were measured with a series of Fiber Bragg Grating(FBG)sensor on the surface of the pipeline to analyze its maximum value and the distribution of the strain.The relatively effective protective measures and its thickness can be determined based on the experiments.The present work can provide significant support for the design and maintenance of submarine pipelines.