scholarly journals EXPECTED DISCHARGE OP IRREGULAR WAVE OVERTOPPING

1968 ◽  
Vol 1 (11) ◽  
pp. 54 ◽  
Author(s):  
Senri Tsuruta ◽  
Yoshimi Goda
Keyword(s):  
Vertical Wall ◽  
Laboratory Data ◽  
Irregular Waves ◽  
Linear Summation ◽  
Wave Overtopping ◽  
Irregular Wave ◽  
Concrete Blocks ◽  
Vertical Walls ◽  
Expected Values ◽  
Sea Wall

An experiment was carried out on the overtopping of mechanically generated irregular waves over vertical walls. The experimental discharge was almost in agreement with the expected discharge which had been calculated with the wave height histogram and the data of regular wave overtopping based on the principle of linear summation. The expected values of overtopping discharge were calculated for various laboratory data, which had been represented in a unified form of non-dimensional quantities. The calculation has yielded two diagrams of expected overtopping discharge, one for the sea wall of vertical wall type and the othei for the sea wall covered with artificial concrete blocks.

scholarly journals APPLICATION OF SMOOTHED PARTICLE HYDRODYNAMICS IN EVALUATING THE PERFORMANCE OF COASTAL RETROFIT STRUCTURES

2018 ◽  
pp. 109 ◽  
Author(s):  
Soroush Abolfathi ◽  
Dong Shudi ◽  
Sina Borzooei ◽  
Abbas Yeganeh-Bakhtiari ◽  
Jonathan Pearson
Keyword(s):  
Numerical Model ◽  
Smoothed Particle Hydrodynamics ◽  
Vertical Wall ◽  
Laboratory Data ◽  
Wave Structure ◽  
Base Case ◽  
Submerged Breakwater ◽  
Wave Overtopping ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

This study develops an accurate numerical tool for investigating optimal retrofit configurations in order to minimize wave overtopping from a vertical seawall due to extreme climatic events and under changing climate. A weakly compressible smoothed particle hydrodynamics (WCSPH) model is developed to simulate the wave-structure interactions for coastal retrofit structures in front of a vertical seawall. A range of possible physical configurations of coastal retrofits including re-curve wall and submerged breakwater are modelled with the numerical model to understand their performance under different wave and structural conditions. The numerical model is successfully validated against laboratory data collected in 2D wave flume at Warwick Water Laboratory. The findings of numerical modelling are in good agreement with the laboratory data. The results indicate that recurve wall is more effective in mitigating wave overtopping and provides more resilience to coastal flooding in comparison to base-case (plain vertical wall) and submerged breakwater retrofit.

scholarly journals VERTICAL SEA WALL CREST MODIFICATIONS FOR OVERTOPPING

2018 ◽  
pp. 71
Author(s):  
Dogan Kisacik ◽  
Gulizar Ozyurt Tarakcioglu ◽  
Cuneyt Baykal ◽  
Gokhan Kaboglu
Keyword(s):  
Urban Areas ◽  
Vertical Wall ◽  
Breaking Wave ◽  
Limited Information ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Wave Basin ◽  
First Results ◽  
Set Up ◽  
Sea Wall

Crest modifications such as a storm wall, parapet or a bullnose are widely used to reduce the wave overtopping over coastal structures where spatial and visual demands restrict the crest heights, especially in urban areas. Although reduction factors of these modifications have been studied for sloped structures in EurOtop Manual (2016), there is limited information regarding the vertical structures. This paper presents the experimental set-up and first results of wave overtopping tests for a vertical wall with several different super structure types: a) seaward storm wall, b) sloping promenade, c) landward storm wall, d) stilling wave basin (SWB), e) seaward storm wall with parapet, f) landward storm wall on the horizontal promenade with parapet, g) landward storm wall with parapet, h) stilling wave basin (SWB) with parapet, under breaking wave conditions. The SWB is made up of a seaward storm wall (may be a double shifted rows) , a sloping promenade (basin) and a landward storm wall. The seaward storm wall is partially permeable to allow the evacuation of the water in the basin.

scholarly journals APPLICATION OF SMOOTHED PARTICLE HYDRODYNAMICS IN EVALUATING THE PERFORMANCE OF COASTAL RETROFIT STRUCTURES

2018 ◽  
Vol 1 (36) ◽  
pp. 109 ◽  
Author(s):  
Soroush Abolfathi ◽  
Dong Shudi ◽  
Sina Borzooei ◽  
Abbas Yeganeh-Bakhtiari ◽  
Jonathan Pearson
Keyword(s):  
Numerical Model ◽  
Smoothed Particle Hydrodynamics ◽  
Vertical Wall ◽  
Laboratory Data ◽  
Wave Structure ◽  
Base Case ◽  
Submerged Breakwater ◽  
Wave Overtopping ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

This study develops an accurate numerical tool for investigating optimal retrofit configurations in order to minimize wave overtopping from a vertical seawall due to extreme climatic events and under changing climate. A weakly compressible smoothed particle hydrodynamics (WCSPH) model is developed to simulate the wave-structure interactions for coastal retrofit structures in front of a vertical seawall. A range of possible physical configurations of coastal retrofits including re-curve wall and submerged breakwater are modelled with the numerical model to understand their performance under different wave and structural conditions. The numerical model is successfully validated against laboratory data collected in 2D wave flume at Warwick Water Laboratory. The findings of numerical modelling are in good agreement with the laboratory data. The results indicate that recurve wall is more effective in mitigating wave overtopping and provides more resilience to coastal flooding in comparison to base-case (plain vertical wall) and submerged breakwater retrofit.

scholarly journals WAVE-INDUCED OVERWASH AND DESTRUCTION OF SAND DUNES

2011 ◽  
Vol 1 (32) ◽  
pp. 34 ◽  
Author(s):  
Jens Figlus ◽  
Nobuhisa Kobayashi ◽  
Christine Gralher ◽  
Vicente Iranzo
Keyword(s):  
Morphological Changes ◽  
Sand Dunes ◽  
Vertical Wall ◽  
Laboratory Data ◽  
Complex Interaction ◽  
Empirical Parameter ◽  
Wave Overtopping ◽  
Dry Zone ◽  
Profile Changes ◽  
Wave Induced

Numerical modeling of the rapid dune profile changes that may occur due to wave overtopping and sediment overwash during a storm is challenging. One of the reasons is the limited amount of available field and laboratory data related to the problem. Another reason is the complex interaction of hydrodynamics, morphological changes and sediment transport in the intermittently wet and dry zone of the dune profile. We modified the cross-shore numerical model CSHORE on the basis of three laboratory overwash tests with different dune geometries in front of a low-crested vertical wall to include the capability to predict profile evolution due to wave overtopping and overwash. Experimental results show that the transition from minor to major overwash is fairly rapid and that the resilience of the dune against destruction by wave-induced overwash is dependent on its geometry. Computed results compare well with the measured hydrodynamics, profile changes, wave overtopping rates and sediment overwash rates, requiring only one empirical parameter to be calibrated. Only the erosion in front of the vertical wall in the last phase of each test is not predicted well by the model. Additional comparisons with field data on profile evolution involving overwash verifies the field capabilities of CSHORE.

IRREGULAR WAVE OVERTOPPING AT VERTICAL WALLS - LEARNING FROM REGULAR WAVE TESTS

2007 ◽  
Author(s):  
Karl-Fr. Daemrich ◽  
Jens Meyering ◽  
Nino Ohle ◽  
Claus Zimmermann
Keyword(s):  
Regular Wave ◽  
Wave Overtopping ◽  
Irregular Wave ◽  
Vertical Walls

scholarly journals IRREGULAR WAVE TESTS FOR COMPOSITE BREAKWATER FOUNDATIONS

1982 ◽  
Vol 1 (18) ◽  
pp. 128 ◽  
Author(s):  
Katsutoshi Tanimoto ◽  
Tadahiko Yagyu ◽  
Yoshimi Goda
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Irregular Waves ◽  
Stability Number ◽  
Regular Waves ◽  
Significant Wave ◽  
Irregular Wave ◽  
Concrete Blocks ◽  
Rubble Mound ◽  
The Stability

The stability of armor units for the rubble mound foundations of composite breakwaters has been investigated under the action of irregular waves. The tests establish that irregular waves are more destructive than regular waves, when the height of regular waves is set equal to the significant wave height. The stability number, defined by Hudson, for quarry stones and concrete blocks with simple shapes is formulated on the basis of irregular wave tests. The stability number is expressed by two parameters of h'7/7]/3 and K, where h' is the crest depth of the rubble mound foundation, #1/3 is the design significant wave height, and K is a parameter for the combined effects of the relative water depth and the relative berm width of the rubble mound foundation to the wavelength. The design mass of armor units can be calculated by the stability equation with the stability number. The application of the proposed method to the results of the irregular wave tests demonstrates that the damage percent for the quarry stones is at most 3.5% at the design condition and the damage progresses rather gradually for the action of higher waves. On the other hand, the damage of the concrete blocks almost jumps beyond the design wave height. In particular, the drastic damage is often caused in the case of high rubble mound foundations. The proposed method is confirmed, however, to be applicable for the ordinary low mound foundations with a sufficient safety.

scholarly journals Estimate of Wave Overtopping Rate on Vertical Wall Using FUNWAVE-TVD Model

2021 ◽  
Vol 33 (6) ◽  
pp. 257-264
Author(s):  
Moon Su Kwak ◽  
Nobuhisa Kobayashi
Keyword(s):  
Numerical Calculation ◽  
Numerical Model ◽  
Calculation Result ◽  
Empirical Formula ◽  
Vertical Wall ◽  
Irregular Waves ◽  
Experimental Result ◽  
Wave Overtopping ◽  
Impulsive Wave ◽  
Numerical Calculation Result

This study established a numerical model capable of calculating the wave overtopping rate of coastal structures by nonlinear irregular waves using the FUNWAVE-TVD model, a fully nonlinear Boussinesq equation model. Here, a numerical model was established by coding the mean value approach equations of EurOtop (2018) and empirical formula by Goda (2009), and adding them as subroutines of the FUNWAVE-TVD model. The verification of the model was performed by numerically calculating the wave overtopping rate of nonlinear irregular waves on vertical wall structures and comparing them with the experimental results presented in EurOtop (2018). As a result of the verification, the numerical calculation result according to the EurOtop equation of this model was very well matched with the experimental result in all relative freeboard (Rc/Hmo) range under non-impulsive wave conditions, and the numerical calculation result of empirical formula was evaluated slightly smaller than the experimental result in Rc/Hmo < 0.8 and slightly larger than the experimental result in Rc/Hmo > 0.8. The results of this model were well represented in both the exponential curve and the power curve under impulsive wave conditions. Therefore, it was confirmed that this numerical model can simulate the wave overtopping rate caused by nonlinear irregular waves in an vertical wall structure.

scholarly journals WAVE OVERTOPPING AT DYKES WITH TOPPED VERTICAL WALL - IMPACTS OF OBLIQUE WAVE ATTACK

2012 ◽  
Vol 1 (33) ◽  
pp. 60
Author(s):  
Nils B. Kerpen ◽  
Torsten Schlurmann
Keyword(s):  
Numerical Models ◽  
Vertical Wall ◽  
Coastal Protection ◽  
Wave Spectra ◽  
Wave Overtopping ◽  
Oblique Wave ◽  
Wave Basin ◽  
Vertical Walls ◽  
The Mean ◽  
Analytical Approaches

Hydraulic model tests at a scale of 1:10 are carried out in a 40 m x 25 m wave basin with a state-of-the-art 3D wave generator in order to collect wave overtopping data at vertical walls and dykes with topped vertical walls. Wave conditions in the near field of the structures, velocities under waves and the mean overtopping discharge are measured. The experiments have been commissioned by the Lower Saxony Water Management, Coastal Defense and Nature Conservation Agency (NLWKN) with the purpose to deliver essential overtopping data for validation of numerical models. Two main geometries are analyzed – each for two specific wave spectra. Overtopping rates are investigated with respect to the remaining freeboard height Rc and the influence of oblique wave attack β{0°, 10°, 30°, 40°, 50°, 60°}. Results are compared with existing analytical approaches. As expected for this special geometrical coastal protection structure, it is examined that overtopping discharges increase with decreasing remaining freeboard. Intensity of the reduction is more dependent on the wave spectra than on the dyke geometry. Mean wave overtopping rate increases with decreasing relative water depth Hm0/d directly in front of the vertical wall. Furthermore, the mean wave overtopping rates decrease with an increasing angle of wave attack β. The correlation between mean wave overtopping rate and freeboard height is given in four newly adapted design formulas, describing the overtopping performance of the two discussed dyke geometries with topped vertical walls.

Large-Scale Experiments of Wave-Overtopping Loads on Walls: Layer Thicknesses and Velocities

2018 ◽  
Author(s):  
Lorenzo Cappietti ◽  
Irene Simonetti ◽  
Andrea Esposito ◽  
Maximilian Streicher ◽  
Andreas Kortenhaus ◽  
...  
Keyword(s):  
Large Scale ◽  
Scale Validation ◽  
Irregular Waves ◽  
Scale Model ◽  
Small Scale ◽  
Wave Loads ◽  
Wave Overtopping ◽  
Large Scale Model ◽  
Vertical Walls ◽  
Set Up

Wave-Overtopping loads on vertical walls, such as those located on top of a dike, have been investigated in several small-scale experiments in the past. A large-scale validation for a mild foreshore situation is still missing. Hence the WALOWA (WAve LOads on WAlls) experimental campaign was carried out to address this topic. This paper, first presents a description of the large-scale model, the measurement set-up and the experimental methodologies, then it focuses on the layer thicknesses and velocities of the flows created on the promenade by the wave overtopping. A set of resistive wave gauges, ultrasonic distance sensors and velocimeters have been used to conduct these measurements. Preliminary data analysis and results, related to a 1000 irregular waves long test, are discussed. The momentum flux of these flows is studied and its implications, for the wave-overtopping loads acting on the vertical walls, are highlighted.

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