Wave induced forces around buried pipelines
TL;DR: In this paper, the wave induced pressure on a pipeline buried in a sandy bed at different burial depth ratios is analyzed. But the results show that wave induced pressures are significantly controlled by the wave period analyzed in terms of the scattering parameter (ka).
About: This article is published in Ocean Engineering.The article was published on 2002-05-01. It has received 34 citations till now. The article focuses on the topics: Submarine pipeline & Wave flume.
Citations
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TL;DR: Zhang et al. as discussed by the authors studied the wave-induced seabed response around a trenched pipeline and found that the response depends on the relative position of the wave and the depth of the seafloor.
Abstract: Zhang, J.; Song, S.; Zhai, Y.; Tong, L., and Guo, Y., 2019. Numerical study on the wave-induced seabed response around a trenched pipeline. Journal of Coastal Research, 35(4), 896–906. Coc...
1 citations
TL;DR: In this paper, the minimum safe burial depth for a 1.5 m to 2.0 m steel pipe is found for transporting crude oil in Kuwaiti marine environment, and the results of this study can be used to select the minimumsafe burial depth in a range of cohesionless soil types from Kuwaiti coastal area, covering hydraulic conductivity in the range of 0.286 to 1.84 mm.
Abstract: Crude oil export is the main business in Kuwait. To transfer the crude oil from land to the ships moored in deeper marine water, submarine pipelines are used. Kuwait is also planning to increase the export to 4.0 million barrel/day in the future and hence need more export terminals, which in turn need more submarine pipelines. One of the challenging problems here is selection of optimum burial depth of the submarine pipeline for the prevailing design condition and soil type. The optimum burial depth of submarine pipeline is the depth at which the pipeline will be stable during the design environmental conditions. It depends on the reduction of wave forces due to burial in the seafloor. Also, the wave forces on the pipeline at any depth of burial depend on the wave characters, hydraulic properties of the sea bed soil and all other marine environmental parameters. Physical modeling is used as tool for assessing the wave forces on the pipeline model for a wide range of wave conditions, for different burial depths and for four types of cohesion-less soil types from Kuwaiti coastal area, covering hydraulic conductivity in the range of 0.286 to 1.84 mm/s. It is found that for all the four soil types, the horizontal wave force reduces with increase in depth of burial, whereas the vertical force generally increases for half buried condition, mainly due to the significant change in the magnitude as well as the phase lag between the hydrodynamic water pressures on the top and bottom of the pipe. Among the soils, well graded soil is found to be good for half burial of pipeline, since the least vertical force is experienced for this soil type. On the other hand, uniformly graded and low hydraulic conductivity soil (like Al-Koot soil with hydraulic conductivity of 0.286 mm/s) attracts the maximum vertical force for half burial case. But, such soil type is found to be good for full burial or further increase of burial, since it is found to attract less vertical wave force, when compared to the soils with high hydraulic conductivity (1.84 mm/s from Shuaiba coast). From the detailed investigations and case study analysis, the minimum safe burial depth for a 1.0 m steel pipe is 1.5 m to 2.0 m for transporting crude oil in Kuwaiti marine environment. The results of this study can be used to select the minimum safe burial depth in a range of cohesionless soils and for a range of marine wave conditions.
1 citations
Cites background from "Wave induced forces around buried p..."
...Madhu Shudan et al. (2002) have carried out experimental investigations to analyze wave induced pressures on a pipeline buried in a permeable seabed....
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TL;DR: In this paper , a detailed investigation to the dynamic response of a ship anchor impacting the suspended section of a submarine cable in order to reduce the risk of cable damage is presented, where a three-dimensional and dual nonlinear model of the anchor affecting a subsea cable is established using ABAQUS finite element analysis software.
Abstract: Suspended submarine cables are prone to likely mechanical damages due to ship anchors, which represent a significant threat to the reliability of power transmission and information communication networks. This paper is aimed at presenting a detailed investigation to the dynamic response of a ship anchor impacting the suspended section a submarine cable in order to reduce the risk of cable damage. In this regard, a three-dimensional and dual nonlinear model of the anchor affecting a subsea cable is established using ABAQUS finite element analysis software. The damage effect due to the ship anchor on the suspended and buried-in-soil sections of the cable is studied. Results show that when a ship anchor hits a suspended section of the subsea cable, the mechanical stress is concentrated at the impacted point and is progressing to both sides of the suspended section with a significant cable deformation. On the other hand, the buried section of the cable suffers from a short impact process, and the deformation is relatively small. To reduce this impact effectively, a detailed technical comparison of two common dumping and filling methods is conducted, and the better protection method is proposed.
1 citations
01 Jan 2018
TL;DR: In this paper, a series of model tests are carried out in the ZJU multifunctional wave-current flume to study on the effects of wave factors on the pore pressure response around clayey silt excavation.
Abstract: Model test of coastal excavations is based on the excavation of Gongbei tunnel located in the Ling-ding Ocean, which is a part of the famous Hongkong-Zhuhai-Macau Bridge project. A series of model tests are carried out in the ZJU multifunctional wave-current flume to study on the effects of wave factors on the pore pressure response around clayey silt excavation. It is shown that the attenuation of the amplitude of the oscillatory and accumulated excess pore pressure are related to the wave height, the wave period and the water depth. Oscillatory excess pore and accumulated excess pore pressure along with maximum seepage path are affected by various wave factors.
References
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TL;DR: In this article, a general theory for the pore pressures and effective stresses induced in a porous bed by ocean waves is developed, where pore fluid as well as the soil skeleton are considered compressible.
Abstract: A general theory for the pore pressures and effective stresses induced in a porous bed by ocean waves is developed. The pore fluid as well as the soil skeleton are considered compressible and the f...
456 citations
TL;DR: The water wave induced seepage force on a pipeline buried in the seabed is investigated in this paper, where the pipeline is assumed to be rigid and not supported by any anchoring force.
105 citations
TL;DR: In this paper, the applicability of traditional porous-media analytical methods to wave-induced flow in beds of sand has been verified experimentally, and the agreement between theory and experiment is found to be quite good.
Abstract: Measurements of the variation of the fluctuating component of pressure have been made in two different beds of sand in a wave channel. The sand was laid from an overhead hopper, and it is shown that the stratification of the bed produced by this method causes the permeability to be different in the vertical and horizontal directions. It is suggested that a similar situation exists in the sea bed. Analytical relationships for the pressure and velocity distributions in such a situation are developed, and the agreement between theory and experiment is found to be quite good. As far as is known, this is the first time that the applicability of traditional porous-media analytical methods to wave-induced flow in beds of sand has been verified experimentally.
104 citations
TL;DR: In this article, a theoretical investigation on the transmission of wave induced pressures into a permeable sea bottom has been performed, assuming that the soil water is compressible, while the grain skeleton is assumed rigid, the resulting theoretical model describes an effective mechanism by which the soil permeability affects the pressure transmission.
Abstract: A theoretical investigation on the transmission of wave induced pressures into a permeable sea bottom has been performed. Assuming that the soil water is compressible, while the grain skeleton is assumed rigid, the resulting theoretical model describes an effective mechanism by which the soil permeability affects the pressure transmission.
82 citations
TL;DR: In this paper, a finite element simulation of the wave-induced hydrodynamic uplift force acting on a submarine pipeline buried in sandy seabed sediments subject to continuous loading of sinusoidal surface waves is presented.
64 citations