• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.649-655
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• 1999

The maximum run-up heights of periodic waves are numerically investigated in this study. Incident waves are sinusoidal and enoidal waves. The maximum run-up height of enoidal wave approaches that of sinusoidal wave as the wave length decreases, while it approaches that of solitary wave as the wave length increases. If wave height is fixed, the maximum run up heights of enoidal waves are always greater than those of sinusoidal waves but smaller than those of solitary waves.

• Journal of Ocean Engineering and Technology
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• v.34 no.4
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• pp.245-252
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• 2020

Wave run-up is an important phenomenon that should be considered in ocean structure design. In this study, the wave run-up of a surface-piercing circular cylinder was calculated in the time domain using the three-dimensional linear and fully nonlinear numerical wave tank (NWT) techniques. The NWT was based on the boundary element method and the mixed Eulerian and Lagrangian method. Stokes second-order waves were applied to evaluate the effect of the nonlinear waves on wave run-up, and an artificial damping zone was adopted to reduce the amount of reflected and re-reflected waves from the sidewall of the NWT. Parametric studies were conducted to determine the effect of wavelength, wave steepness, and the draft of the cylinder on the wave run-up of the cylinder. The maximum wave run-up value occurred at 0°, which was in front of the cylinder, and the minimum value occurred near the circumferential angle of 135°. As the diffraction parameter increased, the wave run-up increased up to 1.7 times the wave height. Furthermore, the wave run-up was 4% higher than the linear wave when the wave steepness was 1/35. In particular, the crest height of the wave run-up increased by 8%.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.479-483
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• 2004

A new calculation method of expected overtopping probability of rubble mound breakwater considering real tide occurrence has been proposed. A calculation method of expected overtopping probability of rubble mound breakwater was proposed by Kweon and Suh (2003). In their calculation, the fluctuation of tidal elevation was expressed by the sinusoidal change that yields the uniform distribution of occurrence frequency. However, the realistic distribution of tidal elevation should influence on the overtopping chance. In this study, the occurrence frequency of tidal elevation obtained from the real sea is included. The tidal elevation used in this study is collected from the east coastal part of Korean peninsular. Analyzing the annual data of the tidal fluctuation measured hourly during 355 days, the distribution of occurrence frequency is formulated utilizing by the normal distribution with one peak. Among the calculation procedures of annual maximum wave height, wave height-period joint distribution, wave run-up height and occurrence frequency of tide, only the annual maximum wave height is again chosen randomly from normal distribution to consider the uncertainty. The others are treated by utilizing the distribution function or relationship itself, It is found that the inclusion of the variability of tidal elevation has great influence on the computation of the expected overtopping probability of rubble mound breakwater. The bigger standard deviation of occurrence frequency is, the lower the overtopping probability of rubble mound breakwater is.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.591-598
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• 2015

A hydraulic characteristics in the surf zone such as wave breaking points, wave set-down, wave set-up, wave-induced currents and run-up heights are studied using the SWASH model during Typhoon NAKRI(1412) in Haeundae Beach. Incident wave conditions is obtained from one-hourly observed wave data by KHOA and irregular wave by JONSWAP spectrum is given as an open boundary condition in the model. A Wave-induced current patterns by the SWASH model is compared with the observed currents and sediment flux patterns in that areas, the calculated maximum wave run-up heights in the model is compared with the video monitoring data, the empirical formula by Stockdon et al. and Mase. A dominant longshore currents toward the east of the beach appears due to the effect of incident wave direction and the geographical features and some rip currents occurs at the central part of the beach. The maximum wave run-up height(1.15 m) by the SWASH model shows a similar pattern with the video monitoring data(1.26 m) and the magnitude shows a similar result(1.33m) by Stockdon et al.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.71-74
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• 1995

Edge wave는 해안선 근처에서 갇힌(trapped) 파의 한 형태로써, 해안선 근처에서의 산사태(Yeh and Chang, 1994) 또는 지진해일(tsunami)이 해안선에 도달한 후 해안선과의 상호간섭(Shuto, 1990)에 의해서 발생한다. Edge wave는 해안선을 따라 최대 처오름 높이(maximum run-up height)를 유지하며 진행하기 때문에 범람으로 인한 인명 및 재산피해를 야기시킬 수 있으므로 이에 관한 정확한 해석은 매우 중요하다. (중략)

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.1
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• pp.69-83
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• 2006

A Level 3 reliability analysis has been performed for wave run-up and overtopping on a sloping seawall. A Monte-Carlo simulation was performed considering the uncertainties of various variables affecting the wave overtopping event. The wave overtopping probability was evaluated from the individual wave run-up by using the wave-by-wave method, while the mean overtopping rate was calculated directly from the significant wave height. Using the calculated overtopping probability and mean overtopping rate, the maximum overtopping volume was also calculated on the assumption of two-parameter Weibull distribution of individual wave overtopping volume. In addition, by changing wave directions, depths, and structure slopes, their effects on wave overtopping were analyzed. It was found that, when the variability of wave directions is considered or the water depth decreases toward shore, wave height become smaller due to wave refraction, which yields smaller mean overtopping rate, overtopping probability and maximum overtopping volume. For the same mean overtopping rate, the expected overtopping probability increases and the expected maximum overtopping volume decreases as approaching toward shore inside surfzone.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.229-232
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• 2008

The Central East Sea Tsunami caused huge damage to the eastern coast of the Korean Peninsula, eapecially Imwon port was damaged relatively strongly beacause of water depth variation which makes the wave concentration on this port. there are many virtual tsunami in east sea which has a possibility of happening. So, it is very important to expect the region which may be damaged by vritual tsunmis. In this study, modified dispersion-correction terms are used. The modified scheme has the advantage of using the constant spatial grid size and time step size even in real topography. Dynamic linking technique and staggered grid system are used. Using this model some cases of virtual tsunami was simulated and check the region which is occured maximum wave heights on the eastern sea of the Korean peninsula.

• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.779-786
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• 2002

A boundary element method with a Lagrangian approach and B-spline technique is employed to investigate characteristics of solitary waves attacking on beach slopes. By comparing numerical solutions with available laboratory measurements, it is shown that the maximum run-up heights of the present model are more agreeable than those of the existing numerical model. Variations of run-up heights and velocity vectors for different slopes are also described. Characteristics of hydrodynamic pressure acting beach slopes are investigated in detail.

• Journal of Korea Water Resources Association
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• v.50 no.9
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• pp.647-652
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• 2017

Many islands are scattered around the southern area of the Korean Peninsula and they may be very vulnerable to unexpected tsunami attacks. During the East Japan Tsunami Event occurred on March 11, 2011, many islands located at the southern area were affected by tsunamis. In this study, maximum run-up heights of solitary waves on a circular island with asymmetrical crest lengths investigated by using a numerical model based on the shallow-water theory. The obtained results could be used by local authorities to establish a defense plan against unexpected tsunami invasion.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.943-953
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• 2021

The propagation of impact wave induced by landslide and debris flow occurred on the slope of lake, reservoir and bays is a three-dimensional natural phenomenon associated with strong interaction of debris flow and water flow in complex geometrical environments. We carried out 3D numerical modeling of such impact wave in a bay using a multiphase turbulence flow model and a rheology model for non-Newtonian debris flow. Numerical results are compared with previous experimental result to evaluate the performance of present numerical approach. The results underscore that the reasonable predictions of both thickness and speed of debris flow head penetrating below the water surface are crucial to accurately reproduce the maximum peak height and free surface profiles of impact wave. Two predictions computed using different initial debris flow thicknesses become different from the instant when the peaks of impact waves fall due to the gravity. Numerical modeling using relatively thick initial debris flow thickness appears to well reproduce the water surface profile of impact wave propagating across the bay as well as wave run-up on the opposite slope. The results show that the maximum run-up height on the opposite slope is not sensitive to the initial thickness of debris flows of same total volume. Meanwhile, appropriate rheology model for debris flow consisting of inviscid particle only should be employed to more accurately reproduce the debris flow propagating along the channel bottom.