Assessment of submarine pipeline damages subjected to falling object impact considering the effect of seabed. (July 2021)

• Record Type: Journal Article
• Authors: Tian, Yinghui; Chai, Weisen; Borgi, Sami El; Zhang, Chunhui; Sun, Liqiang; Xiao, Zhong; Fu, Dengfeng
• Is Part Of: Marine structures. Volume 78(2021)
• Publication Date: 2021-07
• Subjects: Pipelines -- Seabed -- Numerical modelling -- Impact -- Damage; Naval architecture -- Periodicals; Offshore structures -- Periodicals; Architecture navale -- Périodiques; Structures offshore -- Périodiques; Naval architecture; Offshore structures; Periodicals; 620.4162
• DOI: 10.1016/j.marstruc.2021.102963
• Languages: English
• ISSNs: 0951-8339

Abstract

Abstract: Untrenched submarine pipelines lying on the seabed are vulnerable and can be damaged by the impact of falling objects. This may cause significant economic costs for repair and even environmental contamination in case of rupture and oil leakage. This paper presents assessment of submarine pipeline damage subjected to falling object impact considering the effect of seabed through nonlinear explicit dynamic finite element modelling. The numerical model was first verified against existing experimental results and established studies. A total of 209 cases of parametric study was then conducted to assess pipeline damage by accounting for various factors, including object mass, velocity and seabed conditions. The results show that the pipeline damage can be directly related to the impact kinetic energy of the falling object for pipelines sitting on rigid bed. In other words, falling objects with the same impact energy (while mass and velocity may vary) cause the same damage to a pipeline. For a pipeline on a soil seabed, however, this study shows that pipeline damage is no longer simplistically determined by the impact kinetic energy of the falling objects. Falling objects with different mass and velocity may cause different pipeline damages, even though the impact energy is the same. It is interesting to find out that objects with a smaller mass (i.e. higher velocity) tend to cause greater damage than objects with a greater mass (i.e. lower velocity), when the total impact kinetic energy of the falling objects is the same. These observations are explored in this paper, which is explained with the variation of the energy absorption due to the existence of soil seabed. Highlights: This paper investigates the damages of marine pipelines subjected to falling object impact. This paper considers the effects of soil seabed to update the exiting knowledge based on rigid bed. This paper finds the damage is no longer simplistically determined by the impact kinetic energy on soil seabed. A direction relationship between pipeline damage and pipe plastic deformation energy is established.