海底沙波地貌演变及其对管道工程影响研究进展

A Review on Sand Waves Evolution and Its Influence on Pipeline Engineering

海底沙波是一种常见近似规则的起伏地貌形态,通常具有较强的活动性,能引起海底管道的裸露和悬空,进而造成管道的疲劳失效甚至断裂等重大危害。根据近几年海底沙波领域的最新研究成果,介绍了当前海底沙波的主要研究方法,包括现场实测观测、稳定性模型分析和数值计算模拟等的适用性和局限性以及未来发展方向。对海底沙波的成因和迁移机制进行了归纳分析,明确了多种主要的水动力环境因素,以及对于极端天气因素的考虑。从海底管道施工期和服役期分别讨论了海底沙波对于海底管道工程的影响,并建议将沙波活动和局部冲刷两种不同尺度的海床地貌改变耦合分析,以评估海底管道稳定性,最后提出了悬空海底管道的一些有效治理和维护手段。

Sand wave is a rhythmic bed form generally generated on the continental shelf,especially on the coastal seabed,where the waves,current and tides dominate.Sand waves are immobilized and its migration may induce exposure and free spans of submarine pipelines,which may result in the fatigue failure or even fracture of pipeline.In this paper,a review of study methods,mechanics of evolution and migration of sand waves,its influences on the safety and stability of submarine pipelines and the maintenance methods,is conducted.Several research methods for the sand waves,including the field survey,stability analysis and numerical modeling,etc.,and the advantages and limitations are discussed.The main hydro-environments for the formation and migration of sand wave are summarized,and it is also demonstrated that the extreme weather should be taken into account.The influences of the migrating sand waves on the submarine pipeline can be discussed from installation period and operation period,respectively.The global sand wave migration and local scour near the pipeline should be coupled when assessing the stability of the spanning pipeline in sad wave area.Finally,several methods for mitigation and maintenance of the spanning pipeline are summarized.These research results represent the recent progress and behavior of sand wave studies and shall be helpful to the Chinese sand wave and pipeline stability researches in future.