Wave Slam on Horizontal Members of an Offshore Platform

Nash, James M.

doi:10.4043/2500-ms

Cited by 14 publications

(4 citation statements)

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“…Additional papers of interest in regard to the problem described above are Attfield, 1975, Dalton and Nash, 1976, and Kjeldsen and Myrhaug, 1979 z/r The approach described above can be used to calculate the force due to a breaking wave acting on a vertical circular pile, using 3m x /3x in place of 3m /3y, where x is the horizontal coordinate and 3m x /3x is the change in the horizontal component of added mass with immersion of the vertical pile by the breaking wave (Wiegel, 1979). One can calculate the horizontal component of the slowly varying wave-induced force using the Morison equation from y = 0 to y = Yb-^lj, (see Fig.…”

Section: Breaker Forces On Pilesmentioning

confidence: 99%

Forces Induced by Breakers on Piles

Wiegel

1982

Int. Conf. Coastal. Eng.

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This paper consists of three parts. The first part presents a method for analyzing the forces exerted by breaking waves on a cirular pile. The force consists of two components, a slowly varying force and a much larger but very short duration quasi-impact force (probably of the order of 1/100 of a second). The second part is concerned with breaker characteristics, with emphasis being given to the few field data that have been measured. The third part consists of a presentation of some available data on surf zone bottom profile variations with time. Information on all three of these parts is needed for the proper design of a pile supported structure in the surf zone. If the bottom along the site of a proposed pier is sand, an estimate of the variability with time of the profile must be made. The effect of bottom depth and configuration on the height of waves moving shoreward, and the effect of this, in turn, on the wave loading is important in the calculations of wave-induced moments about the bottom. The ability of the structure to withstand these horizontal loads depends in part upon the depth of penetration of the piles. If the bottom varies with time, then calculations of wave characteristics and wave-induced loads on the piles should be made for appropriate bottom configurations.

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Section: Breaker Forces On Pilesmentioning

confidence: 99%

Forces Induced by Breakers on Piles

Wiegel

1982

Int. Conf. Coastal. Eng.

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“…The aspect ratio of typical suction anchors is chosen in various ranges based on different application, as indicated in Table 1. During extreme storms, impact loading characterized by an abrupt and sharp rise in the pullout action becomes the key controlling condition for mooring foundation design [2].…”

Section: Introductionmentioning

confidence: 99%

Numerical model for suction anchor under vertical impact loading

Xu,

Rui,

Zhang

et al. 2024

IOP Conf. Ser.: Earth Environ. Sci.

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In marine engineering, suction anchors are widely employed as the supporting foundation for many types of fixed or floating structures. One of the important control conditions for the service of marine foundations is the impact loading in extreme environments. This study proposes a numerical model to predict the dynamic behavior of suction anchors under impact loading. A mass module is added to the numerical model to quantify the effect of anchor inertia. The t-z springs are positioned along the depth to reflect the soil layer stress and accurately calculate the skirt wall friction. Considering the seepage effect, the differential pressure development, internal soil stress loss and external soil stress enhancement are also reflected. Subsequently, the influence of anchor aspect ratio and loading history are investigated. As the foundation uplift movement is further pronounced, the friction resistance gradually works, resulting in the weakening of inertial force. The existence of pretension loading makes friction resistance take effect earlier, and accelerates its attenuation during the impact loading stage.

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“…This investigation was undertaken (1) to examine the existing theoretical models for detennining wave slam forces on circular cylinders; (2) to furnish data, obtained under controlled laboratory conditions, about forces acting on circular cylinders subjected to impact with a sinusoidally oscillating water surface; (3) to determine the relative importance of the inertia-and drag-dominated forces during fluid impact; and (4) to correlate these data for identifiable wave parameters such ~s the Froude number (N Fr ); the Keulegan-Carpenter number (N K ); and the Reynolds number (N Re ).…”

Section: Original Manuscript Received In Society Of Petroleum Engineersmentioning

confidence: 99%

“…Kaplan and Silbert 2 developed a solution for the forces acting on a cylinder from the instant of impact to full immersion. Dalton and Nash 3 conducted slamming experiments with a 0.5-in.…”

Section: Introductionmentioning

confidence: 99%