scholarly journals PHYSICAL MODEL TESTS OF WAVE OVERTOPPING AND FORCES ON BREAKWATER CROWN WALLS

2018 ◽  
pp. 63
Author(s):  
Leopoldo Franco ◽  
Giorgio Bellotti ◽  
Claudia Cecioni
Keyword(s):  
Physical Model ◽  
Time Lag ◽  
Careful Analysis ◽  
Model Tests ◽  
Horizontal Force ◽  
Empirical Formulas ◽  
Statistical Parameters ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Wave Induced

This paper describes new physical model tests aiming at measuring both wave overtopping and wave induced forces on rubble mound breakwater crown walls. The physical model and the equipment used for the measurements are described in detail. For the completed tests, a detailed analysis is reported, by evaluating the properties of the incoming waves at the toe of the breakwater and some statistical parameters to describe the wave induced forces and pressures on the crown wall. Careful analysis is also carried out to evaluate how the distribution of the pressures changes with time. It is found that the upper part of the wall is subjected to the first large quasi-impulsive action of the wave; the lower part of the wall is afterwards flooded and a quasi-hydrostatic pressure develops along the height of the wave wall. As far as the pressures on the base of the crown wall are concerned, they develop after a quite large time lag after the maximum of the horizontal force. First attempts to correlate the maximum horizontal force with some explanatory variables such as the ratio of the crest freeboard and of the significant wave height of the incoming waves indicate a promising correlation, also in agreement with the existing literature on the topic. The overtopping rate are also measured and compared with empirical formulas. The correlation between the wave induced forces and the average overtopping discharge on the breakwater is also investigated.

scholarly journals LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

2020 ◽  
pp. 15
Author(s):  
Wouter Ockeloen ◽  
Coen Kuiper ◽  
Sjoerd van den Steen
Keyword(s):  
Water Management ◽  
Physical Model ◽  
Large Scale ◽  
Wadden Sea ◽  
Model Tests ◽  
Small Scale ◽  
Water Safety ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

scholarly journals PHYSICAL MODEL TESTS ON WAVE OVERTOPPING AND FLOW PROCESSES ON DIKE CRESTS INFLUENCED BY WAVE-CURRENT INTERACTION

2012 ◽  
Vol 1 (33) ◽  
pp. 34 ◽  
Author(s):  
Stefanie Lorke ◽  
Babette Scheres ◽  
Holger Schüttrumpf ◽  
Antje Bornschein ◽  
Reinhard Pohl
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Longshore Current ◽  
Wind Fields ◽  
Incoming Wave ◽  
Wave Overtopping ◽  
Improve Design ◽  
Physical Model Tests ◽  
Flow Processes ◽  
Run Up

Flow processes like flow depths and flow velocities give important information about erosion and infiltration processes, which can lead to an unstable dike structure and consequently to dike failure. Up to now several physical model tests on wave run-up and wave overtopping are available to adjust and improve design formula for different dike structures. This kind of physical model tests have been performed in the here presented project FlowDike. Its main purpose is to consider two new aspects that could influence the assessment of wave run-up and wave overtopping as well as the flow processes on dikes which have not been investigated yet: longshore current and wind. Especially in estuaries and along coasts, the effect of tidal and storm induced currents combined with local wind fields can influence the incoming wave parameters at the dike toe as well as the wave run-up height, the wave overtopping rate and the flow processes on dikes. This paper will focus on these flow processes on dike slopes and dike crests on an 1:6 sloped dike influenced by oblique wave attack and longshore current.

scholarly journals Experimental Study on the Influence of Berms and Roughness on Wave Overtopping at Rock-Armoured Dikes

2020 ◽  
Vol 8 (6) ◽  
pp. 446 ◽  
Author(s):  
Weiqiu Chen ◽  
Alberto Marconi ◽  
Marcel R. A. van Gent ◽  
Jord J. Warmink ◽  
Suzanne J. M. H. Hulscher
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Physical Model ◽  
Model Tests ◽  
Empirical Equations ◽  
Wave Overtopping ◽  
Dissipation Of Energy ◽  
Physical Model Tests ◽  
Weighting Coefficients

The average overtopping discharge is an important parameter for the design and reinforcement of dikes. Rock armour on the waterside slopes and berms of dikes is widely used to reduce the wave overtopping discharge by introducing slope roughness and dissipation of energy in the permeable armour layer. However, methods for estimating the influence of a rock berm and roughness of rock armour at dikes on the average overtopping discharge still need to be developed and/or validated. Therefore, this study aims to develop empirical equations to quantify the reductive influence of rock armour on wave overtopping at dikes. Empirical equations for estimating the effects of rock berms and roughness are derived based on the analysis of experimental data from new physical model tests. The influence of roughness of the rock armour applied on parts of waterside slopes is estimated by introducing the location weighting coefficients. Results show that the newly derived equations to predict the average overtopping discharge at dikes lead to a significantly better performance within the tested ranges compared to existing empirical equations.

scholarly journals WAVE REFLECTION FROM BERM BREAKWATERS

2020 ◽  
pp. 7
Author(s):  
Karthika Krishna Pillai ◽  
Amir Etemad-Shahidi ◽  
Charles Lemckert
Keyword(s):  
Physical Model ◽  
Wave Reflection ◽  
Model Tests ◽  
Reflection Coefficients ◽  
Data Sets ◽  
Empirical Formulas ◽  
Reflected Waves ◽  
Physical Model Tests ◽  
The Stability

Wave reflection from berm breakwaters is an area less focused as these structures are generally considered to have relatively low reflection levels. However, the reflected waves may compromise the stability of the structure by inducing scour at the toe and may enhance harbour access risk (Zanuttigh et al., 2013). Hence, it is necessary that the reflection coefficients are predicted accurately. Several empirical formulas such as Postma (1989), Alikhani (2000), Zanuttigh and Van der Meer (2008) and Van der Meer and Sigurdarson (2016) have been suggested for the prediction of wave reflection, Kr. In this study, physical model tests were conducted to supplement the existing berm breakwater data sets in the CLASH database (Zanuttigh et al., 2016). The measured reflection coefficients were then compared with those of the existing formulas to evaluate their performance.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/WXIoa_ae-1Y

scholarly journals MODELLING OF WAVE OVERTOPPING AT DIKES USING OPENFOAM

2020 ◽  
pp. 27
Author(s):  
Weiqiu Chen ◽  
Jord Warmink ◽  
Marcel van Gent ◽  
Suzanne Hulscher
Keyword(s):  
Numerical Model ◽  
Physical Model ◽  
Turbulence Model ◽  
Wave Breaking ◽  
Model Calibration ◽  
Empirical Methods ◽  
Empirical Formulas ◽  
Wave Overtopping ◽  
Calibration And Validation ◽  
Physical Model Tests

The average overtopping discharge is an important parameter for the design of flood defences. Several empirical formulas are available for predicting the overtopping discharge at dikes. However, these empirical formulas often have their specific applicable conditions. To complement with the empirical methods, a numerical model has been developed using the open source CFD package OpenFOAM to model the wave overtopping at dikes. Systematic calibration and validation of the numerical model are performed. The influences of the mesh, solver, turbulence model and roughness height on the modelled results of the average overtopping discharge have been investigated during the model calibration. The simulations show that the turbulence model increases the accuracy of the numerical model for predicting the average overtopping discharge under wave breaking conditions. The calibrated model is then validated by comparing the modelled average overtopping discharges with the measured ones from the physical model tests. Results show that the OpenFOAM model is capable of predicting the average overtopping discharge accurately at dikes that have a smooth straight waterside slope.

scholarly journals Experimental Analysis of Wave Overtopping: A New Small Scale Laboratory Dataset for the Assessment of Uncertainty for Smooth Sloped and Vertical Coastal Structures

2019 ◽  
Vol 7 (7) ◽  
pp. 217 ◽  
Author(s):  
Hannah E Williams ◽  
Riccardo Briganti ◽  
Alessandro Romano ◽  
Nicholas Dodd
Keyword(s):  
Time Series ◽  
Physical Model ◽  
Numerical Models ◽  
Vertical Wall ◽  
Model Tests ◽  
Physical Models ◽  
Small Scale ◽  
Wave Condition ◽  
Wave Overtopping ◽  
Physical Model Tests

Most physical model tests carried out to quantify wave overtopping are conducted using a wave energy spectrum, which is then used to generate a free surface wave time series at the wave paddle. This method means that an infinite number of time series can be generated, but, due to the expense of running physical models, often only a single time series is considered. The aim of this work is to investigate the variation in the main overtopping measures when multiple wave times series generated from the same spectrum are used. Physical model tests in a flume measuring 15 m (length) by 0.23 m (width) with an operating depth up to 0.22 m were carried out using a stochastic approach on two types of structures (a smooth slope and a vertical wall), and a variety of wave conditions. Results show variation of overtopping discharge, computed by normalising the range of the discharges at a certain wave condition with the maximum value of the discharge in the range up to 10 % , when the same wave time series is used, but this range increases to 75 % when different time series are used. This variation is found to be of a similar magnitude to both the one found with similar experiments looking at the phenomena in numerical models, and that specified by the confidence bounds in empirical methods.

scholarly journals ADAPTATION WORKS TO AVOID THE FLOODING OF PIAZZA SAN MARCO (VENICE): PHYSICAL MODEL TESTS TO EVALUATE OVERTOPPING DISCHARGE

2020 ◽  
pp. 32
Author(s):  
Luca Martinelli ◽  
Chiara Favaretto ◽  
Matteo Volpato ◽  
Piero Ruol
Keyword(s):  
Water Level ◽  
Physical Model ◽  
Model Tests ◽  
Mitigation Option ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Venetian Lagoon ◽  
A Minor ◽  
Minor Extent

According to the management of the Mo.S.E. system, the water level in the Venetian lagoon is maintained below a certain threshold, that however does not guarantee the complete defense of the main Piazza. Flooding of the Piazza is presently tolerated, although limitedly to a minor extent, and can/will be avoided only thanks to additional adaptation works. One of the possible flooding mechanisms is the wave overtopping, and this note investigates the efficiency, as possible mitigation option, of a small temporary barrier placed along the S. Marco quay.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/wiSF2B81wIM

scholarly journals PORT RESONANCE MITIGATION MODELED INTRODUCING ARJ-R STRUCTURES

2020 ◽  
pp. 38
Author(s):  
Jose A. GONZALEZ-ESCRIVA ◽  
Josep R. MEDINA ◽  
Joaquin M. GARRIDO
Keyword(s):  
Reflection Coefficient ◽  
Physical Model ◽  
Large Scale ◽  
Low Frequency ◽  
Model Tests ◽  
Wave Interference ◽  
Low Frequency Oscillations ◽  
Physical Model Tests ◽  
Similar Cost ◽  
Interference Mechanism

ARJ-R caissons are based on the "long-circuit" concept (Medina et al, 2016) that allows the extension of the destructive wave interference mechanism to mitigate low frequency oscillations without enlarging the width of the caisson. The performance of the ARJ-R caissons is referred to its reflection coefficient (Cr) which was obtained through large-scale physical model tests (Gonzalez-Escriva et al, 2018). In this paper, the effectiveness of Anti-Reflective Jarlan-type structures for Port Resonance mitigation (ARJ-R) has been assessed numerically for the port of Denia (Spain). ARJ-R structures are constructible, with similar dimensions as conventional vertical quay caissons and with a similar cost (15percent more than conventional vertical caisson).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/LomQEVpvjik

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