scholarly journals A Hydraulic Experimental Study of a Movable Barrier on a Revetment to Block Wave Overtopping

2019 ◽  
Vol 10 (1) ◽  
pp. 89 ◽  
Author(s):  
Byeong Wook Lee ◽  
Jihye Seo ◽  
Woo-Sun Park ◽  
Deokhee Won
Keyword(s):  
Physical Experiment ◽  
Field Structure ◽  
Model Structure ◽  
Hydraulic Characteristics ◽  
Allowable Limit ◽  
Wave Overtopping ◽  
Uplift Pressure ◽  
Wave Flume ◽  
Abnormal State ◽  
Impulsive Pressure

This paper presents a design for a movable barrier on the revetment of the Haeundae Marine City in Busan, the Korea. This movable barrier was developed to use as a tourist deck in a normal state and to block wave overtopping in an abnormal state. To carry out the physical experiment in a wave flume, the model structure was reduced to a scale of 1/36 compared to the field structure. The discharge of the wave overtopping, the uplift pressure acting on the under surface of a non-standing barrier, and the wave pressure acting in front of a standing barrier were measured to analyze the hydraulic characteristics of the movable barrier. The results show that the impulsive pressure acts on the movable barrier, although the overtopping discharge is less than the allowable limit. When designing a movable barrier at a full scale, engineers should consider the impulsive pressure to secure the barrier’s stability on the target site.

scholarly journals Examination of Countermeasures against Wave Overtopping around Revetment using Numerical Wave Flume

2007 ◽  
Vol 54 ◽  
pp. 951-955 ◽  
Author(s):  
Koji KAWASAKI ◽  
Masami KIKU ◽  
Kazuya MAEZATO ◽  
Toshihiko KOMESU ◽  
Hiroshi SHIMADA ◽  
...  
Keyword(s):  
Wave Overtopping ◽  
Numerical Wave Flume ◽  
Wave Flume ◽  
Numerical Wave

scholarly journals PRESSURE DISTRIBUTIONS ON A VERTICAL BREAKWATER: EXPERIMENTAL

2011 ◽  
Vol 1 (32) ◽  
pp. 24 ◽  
Author(s):  
Dulce Maria Perez ◽  
Mariana Correa ◽  
Miguel Ortega ◽  
María Clavero ◽  
Miguel Angel Losada
Keyword(s):  
Wave Height ◽  
Wave Length ◽  
Pressure Variation ◽  
Relative Height ◽  
Rectangular Section ◽  
Uplift Pressure ◽  
Wave Flume ◽  
Pressure Distributions ◽  
Total Wave ◽  
Run Up

This work studies the horizontal and uplift pressure distributions over a caisson founded on porous materials, and their dependence on the stone diameter and the height of the foundation. For this, tests at a wave flume with an idealized composite breakwater of rectangular section, varying the depth of the foundation of the caisson and the diameter of the stones, were carried on. Eight resistive gauges and eight pressures sensors were used to measure free surface elevations and horizontal and uplift pressure variation, respectively. Results show that: 1) there exist a “saturation” of the reflection coefficient for B/L>0.4, being B the width of the dike and L the wave length, 2) by using the total wave height measured at the toe of the dike in the analysis, the dispersion of the results is significantly reduced; 3) dimensionless run-up and pressures obtained using total wave height mainly depends on the reflection regime and on the relative height of the foundation; 4) maximum uplift and horizontal forces are not always in phase, and three regimes are identified depending on which force dominates; and 5) the relation between the dimensionless forces with the total wave height at the toe of the dike depends mainly on the reflection regime and on the relative foundation height.

scholarly journals A STUDY ON UPLIFT PRESSURES OF TSUNAMI ACTING ON CEILINGS OF WATER CHANNELS

2017 ◽  
pp. 17
Author(s):  
Tomoyuki Takabatake ◽  
Yukinobu Oda ◽  
Kazunori Ito ◽  
Takahide Honda
Keyword(s):  
Numerical Simulations ◽  
Water Surface ◽  
Water Channel ◽  
Water Channels ◽  
Industrial Facility ◽  
Uplift Pressure ◽  
Trapped Air ◽  
Vertical Barrier ◽  
Predictive Methods ◽  
Impulsive Pressure

When tsunami enters a water channel of an industrial facility, the water surface inside the channel rises and uplift pressures act on the ceiling if it is reached by the water surface. In this study, magnitudes and characteristics of this uplift pressure are investigated both experimentally and numerically. The results show that (1) the uplift pressure comprises an initial impulsive pressure and a following more slowly varying pressure; (2) trapped air reduces the impulsive pressure, and thus attaching a vertical barrier to the ceiling could act as a countermeasure; and (3) the impulsive pressure can be evaluated approximately with conventional predictive methods and by appropriate numerical simulations.

scholarly journals ROUGHNESS FACTOR FOR MULTI-LAYER ARMOUR AS OVERTOPPING ESTIMATOR

2020 ◽  
pp. 25
Author(s):  
Leopoldo Franco ◽  
Yuri Pepi ◽  
Stefano de Finis ◽  
Verdiana Iorio ◽  
Giorgio Bellotti ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Storm Surges ◽  
Random Wave ◽  
Roughness Factor ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Wave Flume ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Nowadays one of the most challenging problem for engineers is to adapt existing coastal structures to climate changes. Wave overtopping is highly sensitive to the increasing extreme water depths due to higher storm surges coupled with sea level rise. One way to face these problems for rubble mound breakwaters is to add one or more layers to the existing armour. Prediction of wave overtopping of coastal structures is presently obtained from empirical formulae in EurOtop (2018). For the case of overtopping over multi-layer armour, no validated method exists, so prediction must be based upon assumptions and judgement, with related uncertainties. This study is focused on the effects of different types of armour, the number of layer and other structural characteristics on the roughness factor f. The main effects of porosity and roughness will be investigated. This paper analyzes the results of several new physical model tests of different rubble mound breakwaters reproduced at the new medium scale random wave flume of the Department of Engineering of Roma Tre University.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/8cOdqkqQ-9s

scholarly journals COMPARISON OF ROCK SEAWALL AND DUNE FOR STORM DAMAGE REDUCTION

2017 ◽  
pp. 31 ◽  
Author(s):  
Hyun Dong Kim ◽  
Nobuhisa Kobayashi ◽  
Xavier Chavez Cardenas
Keyword(s):  
Water Level ◽  
Test Series ◽  
Irregular Waves ◽  
Storm Damage ◽  
Sand Beach ◽  
Wave Overtopping ◽  
Dune Erosion ◽  
Wave Flume ◽  
Damage Reduction

Four test series consisting of 14 tests and 140 runs (each run lasted 400 s) were conducted in a wave flume with a sand beach and a berm in order to compare the effectiveness of a dune and a rock (stone) seawall placed on the foreshore in reducing wave overtopping and sand overwash. The incident irregular waves were kept approximately the same for all the runs. The water level was increased to create dune erosion and crest lowering as well as stone displacement. The dune was effective in eliminating or reducing wave overtopping and overwash in comparison to the corresponding berm with no dune but the narrow dune was destroyed easily as the water level was increased. The stone seawall reduced wave overtopping and overwash even after it was damaged moderately. A stone seawall buried inside a dune was examined in the last test series. The buried seawall functioned like the dune initially and like the seawall after the sand on the seawall was eroded by overtopping waves. The buried seawall combines the aesthetics of the dune and the robustness of the stone seawall.

scholarly journals CLOSELY SPACED PILE BREAKWATER AS A PROTECTION STRUCTURE AGAINST BEACH EROSION

1968 ◽  
Vol 1 (11) ◽  
pp. 39 ◽  
Author(s):  
Taizo Hayashi ◽  
Masataro Hattori ◽  
Masujiro Shirai
Keyword(s):  
Wave Theory ◽  
Beach Erosion ◽  
Hydraulic Characteristics ◽  
Fall Velocity ◽  
Wave Flume ◽  
Scouring Depth ◽  
The Mean ◽  
Bed Material ◽  
The Waves ◽  
Transmission And Reflection

The theory for the transmission and reflection of the waves at the closely spaced pile breakwater has been developed by the use of shallow water wave theory of small amplitude. Experiment on the hydraulic characteristics of the breakwater has been performed in a two dimensional wave flume. The agreement between the theory and the experiment is pretty good with respect to the coefficients of transmission and reflection of waves, and also to the shoreward velocity of the jet discharged from a space between any two adjacent piles. Experiment was also made on the local scouring at the foot of the clocely spaced pile breakwater. The maximrai scouring depth at the foot of the breakwater relates closely to the ratio of the velocity of the jet to the mean fall velocity of bed material. The relation between the maximum scouring depth and the power of the jet is discussed.

scholarly journals WAVE OVERTOPPING ON RUBBLE MOUND BREAKWATERS

1988 ◽  
Vol 1 (21) ◽  
pp. 57 ◽  
Author(s):  
Pierliugi Aminti ◽  
Leopoldo Franco
Keyword(s):  
Hydraulic Model ◽  
Model Tests ◽  
Geometric Parameters ◽  
Random Wave ◽  
Wave Overtopping ◽  
Wave Flume ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

The paper gives the results of an extensive series of hydraulic model tests carried out in a random wave flume, in order to study the effects on wave overtopping of the main geometric parameters of a typical rubble mound breakwater with crown wall. The results have been compared with those from other studies and analyzed with different methods. Generalized design diagrams and formulae for the prediction of overtopping discharges are finally given for a large number of popular breakwater configurations.

APPLYING A NUMERICAL WAVE FLUME TO PREDICT WAVE OVERTOPPING

2019 ◽  
Author(s):  
STEF BOERSEN ◽  
OLAF SCHOLL ◽  
NIELS JACOBSEN ◽  
COCK VAN DER LEM
Keyword(s):  
Wave Overtopping ◽  
Numerical Wave Flume ◽  
Wave Flume ◽  
Numerical Wave

scholarly journals AVERAGE AND WAVE-BY-WAVE OVERTOPPING PERFORMANCE OF STEEP LOW-CRESTED STRUCTURES

2018 ◽  
pp. 77 ◽  
Author(s):  
David Gallach-Sánchez ◽  
Peter Troch ◽  
Andreas Kortenhaus
Keyword(s):  
Change Process ◽  
Coastal Protection ◽  
Knowledge Gap ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Wave Flume ◽  
Wave Energy Converters ◽  
Individual Wave ◽  
The Individual ◽  
Steep Slopes

Wave overtopping is a key process in coastal protection. The assessment of the wave overtopping rates is an important aspect in the design of coastal structures. In this paper, the focus is on steep low-crested structures, which include structures with steep slopes up to the limit case with vertical structures, with small relative freeboards up to the case with zero freeboards. This type of structures is of use for coastal protection in the case of sea level rise within climate change process and for overtopping wave energy converters. A literature review of the overtopping knowledge available for steep low-crested structures is carried out, identifying a knowledge gap. To fill this knowledge gap, 2D hydraulic model tests were performed at the wave flume of the Department of Civil Engineering at Ghent University, measuring wave conditions and the overtopping performance. Average and individual wave overtopping were analysed and compared to existing prediction formulae. Inaccuracies in the existing prediction formulae are detected and studied, and enhanced prediction formulae are presented for the average overtopping and the probability distribution of the individual overtopping volumes. The new prediction formulae improve the accuracy of wave overtopping volumes for steep low-crested structures range while maintaining the accuracy for other types of structures. The improved understanding of the overtopping behaviour allows a safer design of coastal structures.

scholarly journals 2D OVERTOPPING AND IMPACT EXPERIMENTS IN SHALLOW FORESHORE CONDITIONS

2018 ◽  
pp. 67
Author(s):  
Vincent Gruwez ◽  
Ine Vandebeek ◽  
Dogan Kisacik ◽  
Maximilian Streicher ◽  
Corrado Altomare ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Surf Zone ◽  
High Spatial Resolution ◽  
Wave Structure ◽  
High Energy ◽  
Water Levels ◽  
Wave Transformation ◽  
Wave Overtopping ◽  
Typical Situation ◽  
Wave Flume

This paper introduces the 2D experiments conducted for the CREST project in the wave flume of Ghent University. The experiments focus on wave interactions with low-crested sea dikes fronted by a shallow foreshore and mildly to steeply sloping beaches, which is a very typical situation along the Belgian coast. Foreshore slopes of 1/20, 1/35, 1/50 and 1/80 were tested for a range of low to high energy wave conditions, a variation in wave steepness and two water levels. The main goal was to obtain a dataset in which the effects of the infragravity waves on the wave-structure interactions (i.e. wave overtopping and impact forces) can be studied. The tests included high spatial resolution surface elevation measurement tests, which is new for beaches including a dike in the inner surf zone. From the first results it became clear that the foreshore slope influences the wave transformation up to the dike toe. The influence is apparent comparing to existing (semi-) empirical models for prediction of the spectral wave period at the dike toe and wave overtopping at the dike crest. The high spatial resolution data show a steep increase in infragravity significant wave height in the very shallow area in front of the dike.

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