姜逢源, 赵玉良, 谭俊哲, 董胜. 海床土体减缓坠物对海底管道撞击作用的研究[J]. 工程力学, 2019, 36(5): 235-245. DOI: 10.6052/j.issn.1000-4750.2018.03.0183
引用本文: 姜逢源, 赵玉良, 谭俊哲, 董胜. 海床土体减缓坠物对海底管道撞击作用的研究[J]. 工程力学, 2019, 36(5): 235-245. DOI: 10.6052/j.issn.1000-4750.2018.03.0183
JIANG Feng-yuan, ZHAO Yu-liang, TAN Jun-zhe, DONG Sheng. STUDY ON THE EFFECT OF SEABED SOIL ON RELIEVING DAMAGE OF SUBMARINE PIPELINES IMPACTED BY DROPPED OBJECTS[J]. Engineering Mechanics, 2019, 36(5): 235-245. DOI: 10.6052/j.issn.1000-4750.2018.03.0183
Citation: JIANG Feng-yuan, ZHAO Yu-liang, TAN Jun-zhe, DONG Sheng. STUDY ON THE EFFECT OF SEABED SOIL ON RELIEVING DAMAGE OF SUBMARINE PIPELINES IMPACTED BY DROPPED OBJECTS[J]. Engineering Mechanics, 2019, 36(5): 235-245. DOI: 10.6052/j.issn.1000-4750.2018.03.0183

海床土体减缓坠物对海底管道撞击作用的研究

STUDY ON THE EFFECT OF SEABED SOIL ON RELIEVING DAMAGE OF SUBMARINE PIPELINES IMPACTED BY DROPPED OBJECTS

  • 摘要: 海底管道受坠物撞击的损伤分析中,海床土体是不宜忽略的因素。基于耦合欧拉-拉格朗日算法(CEL法),该文建立了模拟坠物撞击海底管道过程中土体变形的有限元模型,并进行了物理模型试验,二者结果吻合较好。针对粘土海床,分析了海床柔性、海床土质、管道埋深、摩擦及坠物形状对海底管道损伤的影响。研究表明:对于裸置管道,海床柔性使一部分撞击能量转化为管道的整体变形,减轻管道局部损伤;对于埋置管道,基于软件的二次开发,考虑了正常固结粘土及均质粘土两种情况,二者的安全埋深相差较大。综合考虑上述土质的影响,2 m的埋深可提供有效的保护;埋深超过1 m时,坠物与土体间的摩擦系数对管道损伤的影响更加明显;形状尖锐的坠物受到土体的阻力较小,对管道造成的损伤程度较大。不同形状的坠物撞击管道时,管道的变形特征存在差异。研究结果对管道的风险评估及安全埋深设计具有指导意义。

     

    Abstract: Seabed plays an important role in the analysis of submarine pipeline subjectd to impact loads. Based on the coupled Eulerian-Lagrangian method (CEL method), a finite element numerical model is established to simulate the soil deformation involved in the impact process. Meanwhile, physical model tests are carried out. The numerical simulation results show good agreement with test results. Aiming at seabed in clay, a series of influence factors on pipeline damage have been analyzed, including the seabed flexibility, soil property, embedment depth, friction, and dropped object shape. For pipelines resting on seabed surface, part of the impact energy will be dissipated through pipeline global deformation due to bed flexibility, which can relieve the pipeline local damage. For buried pipelines, either the normally consolidated clay or the homogeneous clay is considered. The safe embedment depth of these two conditions differs significantly. Considering the aboved soil conditons, an embedment depth of approximately two meters can provide effective protection for pipelines. The friction coefficient between the dropped object and soil has influence on the dissipation of impact energy and pipeline damage, which is signficant when the embedment depth exceeds one meter. Dropped object in sharp shape can casue servere damage because of less resitance from soil. Besides, there are some differences between deformation characteristics of pipelines, which are influenced by dropped objects in various shapes. The research results are expected to provide reference for risk assessment and safe embedment depth design of submarine pipelines.

     

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