FIELD AND MODEL STUDY ON THE PROTECTION OF RECREATIONAL BEACH AGAINST WAVE ACTION

The heightening of a sea wall is often proposed for the purpose of decreasing the amount of wave-overtopping. In a recreation beach, however, the heightening of sea wall is undesirable from the view-point of environmental preservation and beach utilization. In this paper, instead of it, a proposal is made of the sea wall with a wide frontal step as well as the widening of beach by artificial nourishment. The frontal step is not only effective to decrease the amount of wave-overtopping, but also serves as a promenade for visitors. The widening of beach is known to serve to decrease wave-overtopping as well as to increase the utility for recreation. However, the protection of the nourished beach itself becomes sometimes a difficult problem. In this paper, the hydraulic characteristics of a wide frontal step and the effect of several protective measures for the nourished beach are described on the basis of model and field tests conducted for the improvement of Suma Beach. Suma Beach is a recreational beach situated west of Kobe Port as shown in Fig. 1. The shore-line is about 2 km long and runs from east to west (Fig.11). The beach profile, as shown in Fig.2, has the narrow backshore at about 3 m above L.W.L. and a small step at about 1.5 m below L.W.L. The beach slope is 1/10 in the foreshore, 1/25-1/30 between 2 and 5 m below L.W.L and 1/60-1/80 in the offshore beyond about 6 m below L.W.L. The waves are predominant from the direction of SSW so that the beach materials tend to move eastward along the shore.

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Field and Model Study on the Protection of Recreational Beach against Wave Action

Coastal Engineering 1974 ◽

10.1061/9780872621138.087 ◽

1974 ◽

Author(s):

Shoji Sato ◽

Norio Tanaka

Keyword(s):

Wave Action ◽

Model Study ◽

Recreational Beach

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Experimental Study and Numerical Analysis of Sihui Metro Depot and the Superstructure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.226-228.176 ◽

2012 ◽

Vol 226-228 ◽

pp. 176-180

Author(s):

Jing Zhang ◽

Bin Zhang ◽

Ying Hua Liu ◽

Long Qi Wang ◽

Yu Bin Wu

Keyword(s):

Time History ◽

Field Tests ◽

Element Model ◽

Test Analysis ◽

3 Dimensional ◽

Dimensional Finite Element ◽

Calculation Results ◽

History Of ◽

The Given ◽

The Waves

Field tests were carried out on Sihui metro depot of Beijing metro line 1 and its superstructure. The acceleration time history of sleepers and floors of the building was obtained, and the waves-propagation laws of building were studied through the tests. Test analysis shows that the structure vibrations show zigzag tendencies ascends with the height of the building. Based on current situation of Sihui metro depot, a metro-soil-building 3-dimensional finite element model is established on ANSYS. By using actual acceleration of sleepers as inputs, the dynamic responds rule of the superstructure is obtained. Compared calculation results with the experimental results, the given numerical model can predict the vibrations of the building induced by moving trains quite well. This method can provide guidance and technical support for future development of superstructure.

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A Cost-Effective Method to Reproduce the Morphology of the Nearshore and Intertidal Zone in Microtidal Environments

Remote Sensing ◽

10.3390/rs12111880 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1880

Author(s):

Stefano Furlani ◽

Valeria Vaccher ◽

Vanja Macovaz ◽

Stefano Devoto

Keyword(s):

Intertidal Zone ◽

Field Tests ◽

Cost Effective ◽

Time Lapse ◽

3D Models ◽

The North ◽

Cost Effective Method ◽

Photogrammetric Method ◽

The Difference ◽

Sea Wall

The photogrammetric method is widely used in coastal areas and in submerged environments. Time-lapse images collected with unmanned aerial vehicles are used to reproduce the emerged areas, while images taken by divers are used to reproduce submerged ones. Conversely, 3D models of natural or human-made objects lying at the water level are severely affected by the difference in refractive index between air and seawater. For this reason, the matching of 3D models of emergent and submerged coasts has been very rarely tested and never used in Earth Sciences. The availability of a large number of time-lapse images, collected at the intertidal zone during previous snorkel surveys, encouraged us to test the merging of 3D models of emerged and submerged environments. Considering the rapid and effective nature of the aforementioned program of swim surveys, photogrammetric targets were not used during image acquisition. This forced us to test the matching of the independent models by recognizing prominent landforms along the waterline. Here we present the approach used to test the method, the instrumentation used for the field tests, and the setting of cameras fixed to a specially built aluminum support console and discuss both its advantages and its limits compared to UAVs. 3D models of sea cliffs were generated by applying structure-from-motion (SfM) photogrammetry. Horizontal time-lapse images, collected with action cameras while swimming parallel to the coastline at nearly constant velocity, were used for the tests. Subsequently, prominent coastal landforms were used to couple the independent models obtained from the emergent and submerged cliffs. The method was pilot tested in two coastal sites in the north-eastern Adriatic (part of the Mediterranean basin). The first site was a 25 m sea wall of sandstone set within a small harbor, while the second site was a 150 m route below plunging limestone cliffs. The data show that inexpensive action cameras provide a sufficient resolution to support and integrate geomorphological field surveys along rocky coastlines.

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HYDRAULIC MODEL TESTS ON WAVE OVERTOPPING AT THE HISTORICAL SEA WALL OF BALTRUM

Coastal Engineering 2008 ◽

10.1142/9789814277426_0242 ◽

2009 ◽

Author(s):

Holger Blum ◽

Andreas Kortenhaus ◽

Frank Thorenz

Keyword(s):

Hydraulic Model ◽

Model Tests ◽

Wave Overtopping ◽

Sea Wall

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VERTICAL SEA WALL CREST MODIFICATIONS FOR OVERTOPPING

Coastal Engineering Proceedings ◽

10.9753/icce.v36.structures.71 ◽

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.

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EXPECTED DISCHARGE OP IRREGULAR WAVE OVERTOPPING

Coastal Engineering Proceedings ◽

10.9753/icce.v11.54 ◽

1968 ◽

Vol 1 (11) ◽

pp. 54 ◽

Cited By ~ 4

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.

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A NUMERICAL SIMULATION OF THE WOS AND THE WAVE PROPAGATION ALONG A COASTAL DIKE

Coastal Engineering Proceedings ◽

10.9753/icce.v33.waves.49 ◽

2012 ◽

Vol 1 (33) ◽

pp. 49 ◽

Cited By ~ 1

Author(s):

Panayotis Prinos ◽

Maria Tsakiri ◽

Dimitris Souliotis

Keyword(s):

Numerical Simulation ◽

Wave Propagation ◽

Free Surface ◽

Numerical Models ◽

Field Measurements ◽

Air Entrainment ◽

Empirical Relationships ◽

Wave Overtopping ◽

Unsteady Rans ◽

The Waves

Wave overtopping and the propagation of the waves on the crest and the landward slope of a coastal dike is investigated numerically. Wave overtopping conditions are simulated using the concept of the Wave Overtopping Simulator (WOS). Two numerical models of the WOS are constructed using the FLUENT 6.0.12 (FLUENT Inc. 2001) and the FLOW 3D 9.4 (FLOW 3D 2010) CFD codes. The former simulates the WOS without accounting for air entrainment while the latter accounts for air entrainment. The unsteady RANS equations, the RNG k-ε turbulence model and the VOF method are solved numerically, for "tracking" the free surface and the head of the "current" from the dike crest to the landward dike slope. The computed results from the two models are compared with each other and also against field measurements and proposed empirical relationships (Van der Meer et al. 2010).

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THE RELATIONSHIP BETWEEN WAVE ACTION AND BEACH PROFILE CHARACTERISTICS

Coastal Engineering Proceedings ◽

10.9753/icce.v7.14 ◽

2011 ◽

Vol 1 (7) ◽

pp. 14 ◽

Cited By ~ 2

Author(s):

P.H. Kemp

Keyword(s):

Rational Design ◽

Break Point ◽

Coarse Sand ◽

Beach Erosion ◽

Beach Profile ◽

Model Study ◽

Materials Used ◽

Profile Characteristics ◽

The Relationship ◽

The Waves

The rational design of coast protection works requires a knowledge of the behaviour of the beach under natural conditions. The understanding of the relationship between the waves acting on the beach and the characteristics of the beach profile produced, is thus a necessary preliminary to the analysis of the causes of beach erosion and the evaluation of the effect of projected remedial measures. The present paper describes the results of a series of preliminary hydraulic model experiments carried out by the author prior to a model study of the behaviour of groynes in stabilising beaches. Most of the beach materials used represented coarse sand or shingle in nature. The results demonstrate the fundamental importance of the "phase difference" in terms of wave period between the break-point and the limit of uprush, in relation to flow conditions, cusp formation, and the change from "step" to "bar" type profiles. Within the limits of the experiments an expression connecting the breaker height, beach profile length, and grain diameter is developed, and its implications examined in relation to beach slope, and to the previous "wave steepness" criterion for the change from step to bar type profiles. Observations are included on the rate of recession of a shoreline due to the onset of more severe wave conditions.

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Numerical Simulations of the Hydraulic Performance of a Breakwater-Integrated Overtopping Wave Energy Converter

Journal of Marine Science and Engineering ◽

10.3390/jmse7020038 ◽

2019 ◽

Vol 7 (2) ◽

pp. 38 ◽

Cited By ~ 6

Author(s):

Giuseppina Palma ◽

Sara Mizar Formentin ◽

Barbara Zanuttigh ◽

Pasquale Contestabile ◽

Diego Vicinanza

Keyword(s):

Wave Energy ◽

Wave Reflection ◽

Energy Converter ◽

Wave Overtopping ◽

Energy Capture ◽

Multifunctional Device ◽

Average Wave ◽

Sloping Plate ◽

The Waves ◽

Harbour Area

OBREC is the acronym that stands for Overtopping Breakwater for Energy Conversion. It is a multifunctional device aimed to produce energy from the waves, while keeping the harbour area protected from flooding. In this paper, the inclusions of a berm to reduce wave reflection, the shape of the sloping plate to maximise wave overtopping and the reservoir width and the crown wall shape to maximise wave energy capture while keeping the harbour safety were analysed to optimize the hydraulic and structural performances of the device. Several configurations were numerically investigated by means of a 2DV RANS-VOF code to extend the results already obtained during previous experimental campaigns. The wave reflection coefficient, the average wave overtopping flows and the wave loadings along the structure are computed, compared with existing formulae and discussed with reference to the OBREC prototype installed in the Port of Naples.

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