• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.11 no.2
• /
• pp.87-94
• /
• 1999

The Morison's formula has been commonly used in the determination of wave forces of sinusoidal waves acting on coastal or ocean structures of pile-supported type. In the case that plunging breakers are incident, the structures are subjected to impulsive breaking wave forces which are normally much larger than the Morison's. However, the impulsive breaking wave forces act in a very short time, and hence a dynamic structural analysis should be done to determine whether or not to include the forces in the design force items. In the present study, numerical methods for calculating the dynamic response of a vertically located cylindrical pile are developed. Static and dynamic displacements are then compared through several example analyses varying the structural properties of pile.

• Journal of Ocean Engineering and Technology
• /
• v.14 no.1
• /
• pp.6-10
• /
• 2000

In this paper various methods of determining of wave loads acting ofshore structures including impact load due to breaking wave are studied and corresponding model test was performed. In the theoretical approach wave load by nonbreaking wave and impact load by breaking wave is determined by Morrison's equation Goda's equation and impact wave equation, In the experimental approach wave load by nonbreaking wave acting on cylindrical pile used in offshore structures is determined by measuring the strain on a cylindrical pile and compared with theoretical calue. in the numerical approach impact load by breaking wave acting on a modeled cylindrical pile is calculated by usign ANSYS FEM program and compared with theoretical value. It is found that the experimental and numerical results are comparable to theoretical results, Thus the determination of wave load acting on offshore structures can be obtained by a proposed methods and it acceptable.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.11 no.3
• /
• pp.141-148
• /
• 1999

The magnitude of breaking wave forces given by plunging breakers incident on a pile structure is much greater than the forces calculated by Morison's formula, but those forces may act on pile for very short duration in the range of a few multiples of 0.01 second. Hence, a dynamic analysis for the impact forces of breaking waves may be necessary for the accurate determination of pile displacements in the first stage of design. The time series of the impact force along the pile length is thus required, which may be estimated from the pressure distribution. In the present study, breaking wave pressures are measured for a vertical pile at real field which is easily subjected to plunging breakers in stormy weather conditions. The measured data are analyzed and compared with other results to quantify the characteristics of breaking wave pressures in real fields.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.19 no.1 s.71
• /
• pp.105-111
• /
• 2006

Dolphin mooring system can be a good candidate for the VLFS fastening system in view point of strength and effectiveness. In the design process of the dolphin system, precise calculation of the wave forces and the subsequent selecting the proper number of the piles adopted are one of the main factors. In this paper, one of the design process of the dolphin system is investigated and a proper configuration of the system is derived based on the structural characteristics of the system that was obtained through the structural analysis of the basic pile element confronted to the external loadings including wave impact load. It was found that lot the better design of ihe mooring system for VLFS, mono pile mooring system is more recommendable in a specific condition than other multi piles mooring system.