scholarly journals REFLEKSI GELOMBANG PADA PEMECAH GELOMBANG TENGGELAM BLOK BETON BERKAIT

2018 ◽  
Vol 9 (1) ◽  
pp. 33-42 ◽  
Author(s):  
I Ketut Dharma Setiawan ◽  
Juventus Welly Radianta Ginting
Keyword(s):  
Concrete Block ◽  
Coastal Protection ◽  
Block Type ◽  
Wave Forces ◽  
Research Subject ◽  
Submerged Breakwater ◽  
Experimental Station ◽  
Processing Data ◽  
Wave Generator ◽  
Resource Research

When a large dimension of rock needed for an armored layer of breakwater, the scarcity of it became a major adversity, because of that many research subject of using concrete as a substitute for rock performed. One of the research are the usage of concrete block for submerged breakwater as a method for avoiding a very large concrete block, but still able to withstood wave forces. The key is in the interlocking of each concrete block so it could achieve the desired result with a lesser dimension concrete block. The research was performed in Laboratory of Coastal Experimental Station, Water Resource Research Center, using a 2D channel. The facility used were flume channel, regular wave generator machine, wave dumper, wave probe, and computer for processing data. The experiment indicate that the wave energy attenuation depends on the dimension of interlocking concrete block type submerged breakwater. The dimension represented in the form of relation of the distance of water level to structures crest and the crests width. The breakwater performance of the concrete block is quite useful as an underwater coastal protection building viewed from reflection with a reflection coefficient of 34.7% at (h?d) / h = 0 and the peak width of B = 2.0

scholarly journals Evaluating the feasibility and advantage of a multi-purpose submerged breakwater for harbor protection and benthic habitat enhancement at Kahului Commercial Harbor, Hawai‘i: case study

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Yuko Stender ◽  
Michael Foley ◽  
Ku’ulei Rodgers ◽  
Paul Jokiel ◽  
Amarjit Singh
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Ecological Impact ◽  
Coastal Protection ◽  
Benthic Habitat ◽  
Engineering Structures ◽  
Camera System ◽  
Reef Environment ◽  
Submerged Breakwater ◽  
Coral Reef Environment

AbstractConstruction of breakwaters provides an engineering solution for coastal protection. However, little effort has been made toward understanding the ecological impact on local coral reef ecosystems and developing engineering structures that would enhance the coral reef environment. A submerged breakwater proposed for Kahului Commercial Harbor, Hawai‘i, provided an opportunity to design a multi-purpose ‘reef structure’ to mitigate wave impacts while providing new coral reef habitat. This design involved ecological and environmental considerations alongside engineering principles, serving as a model for environmentally sound harbor development. This field study evaluated environmental conditions and reef community composition at the proposed site in a gradient extending outward from the harbor, using in situ data with multivariate analyses. Benthic and topographic features in the area were assessed using a towed drop camera system to relate to biological factors. Results that support breakwater topography should follow the natural spur and groove and depth of the adjacent reef and orient with wave direction. A deep area characterized by unconsolidated substrata and low coral cover would be replaced with the shallow, sloping hard bottom of the breakwater, and provide an exemplary area for corals to flourish while protecting the harbor from large ocean swells. Surfaces on shallow sloping hard bottoms receive higher levels of irradiance that benefits coral growth. Optimal levels of water motion facilitate sediment removal and promote coral recruitment and growth. The design of the Kahului Harbor submerged multi-purpose structure serves as a model for design of shoreline modification that enhances, rather than degrades, the local coral reef environment.

Optimal sinusoidal submerged breakwater for coastal protection

2021 ◽  
Author(s):  
Muh. Fadhel Atras ◽  
Raynaldi Lalang ◽  
Ikha Magdalena
Keyword(s):  
Coastal Protection ◽  
Submerged Breakwater

scholarly journals Coastal protection work for Batu Mejan Beach, Bali

2019 ◽  
Vol 276 ◽  
pp. 04019
Author(s):  
Pujianiki Ni Nyoman ◽  
Astawa Diputra I Gede ◽  
Jayantari Made W ◽  
Mataram INK
Keyword(s):  
Wave Energy ◽  
Protective Layer ◽  
Minimum Cost ◽  
Public Works ◽  
Coastal Protection ◽  
Submerged Breakwater ◽  
The Public ◽  
International Tourist ◽  
Tourism Destinations ◽  
The Cost

Batu Mejan Beach is an international tourist destination located in the Canggu area of Badung regency, Bali. Due to erosion problems of Batu Mejan Beach the local government installed a revetment system to protect the coast. However, the revetment that was built before for the Batu Mejan Beach is currently ineffective and damaged. To determine the parameters for the construction of a new coastal protection system, the wave energy occurring at the site was evaluated initially as part of this study. A Submerged breakwater with a tetrapod for a protective layer was then chosen as the alternative to reduce the wave energy before reaching the shore and to reduce erosion as well as further deterioration of the existing revetment. A Submerged breakwater is suitable in coastal areas that are used as tourism destinations because the submerged breakwater construction is under the water, therefore the beauty of the beach will not be interrupted. Four models were made with variations in the width and elevation of the breakwater peak. The model was selected which has the minimum value of transmission coefficient and minimum cost. The cost budget plan was determined by using the analytical list of the Public Works and Housing Regulations of 2016. From the analysis, a model was selected with a submerged breakwater height of 2.45 m, length of 110 m, distance gap of 55 m, and the budget of IDR 17,861,989,813.

Estimate of Storm Induced Beach Erosion Through the ETS Approach

2008 ◽  
Author(s):  
Rosaria E. Musumeci ◽  
Carla Faraci ◽  
Felice Arena ◽  
Enrico Foti
Keyword(s):  
Return Period ◽  
Extreme Events ◽  
Coastal Erosion ◽  
Beach Erosion ◽  
Coastal Protection ◽  
Shoreline Retreat ◽  
Submerged Breakwater ◽  
The One

In the present paper the risk of beach erosion is evaluated by applying the Equivalent Triangular Storm (ETS). The selected case study is ‘La Plaja’ beach located in the South of Catania, Sicily. The proposed approach has shown that when the ETS model is applied, a shoreline retreat has been found which on average overestimates the one obtained by means of actual storm data of about 35%. The model has been applied for the determination of the return period of shoreline recession due to beach erosion during extreme events in order to recover risk maps, which can provide useful information in the planning of coastal interventions. Finally the model has been applied to predict the shoreline retreat in the presence of a submerged breakwater, confirming that the introduction of such coastal protection work strongly limits the risk of coastal erosion.

Analysis of water wave interaction with a submerged quarter-circular breakwater using multipole method

2020 ◽  
Vol 234 (4) ◽  
pp. 846-860
Author(s):  
Ai-jun Li ◽  
Yong Liu ◽  
Zuo-rui Lyu
Keyword(s):  
Water Wave ◽  
Series Solution ◽  
Velocity Potential ◽  
Separation Of Variables ◽  
Wave Interaction ◽  
Wave Forces ◽  
Submerged Breakwater ◽  
Circular Arc ◽  
Internal Fluid ◽  
Multipole Expansion Method

This article studies water wave interaction with a submerged quarter-circular breakwater based on potential theory and multipole expansion method. The obliquely and normally incident waves are independently considered. The series solution of velocity potential in the external fluid domain is expressed through the multipole expansions, while the series solution of velocity potential in the quarter-circular internal fluid domain is obtained through the separation of variables. Then, the unknown coefficients in the series solutions are determined by matching the boundary conditions between external and internal fluid domains. The calculation methods for the reflection and transmission coefficients of the submerged quarter-circular breakwater as well as the horizontal and vertical wave forces on the breakwater are presented. The wave forces acting on the submerged breakwater with a seaside quarter-circular-arc and that with a leeside quarter-circular-arc are compared. The hydrodynamic quantities of the submerged quarter-circular breakwater are also compared with those of the submerged semi-circular breakwater. In addition, the effects of breakwater radius, incident frequency, and incident angle on the hydrodynamic quantities of the quarter-circular breakwater are clarified. Valuable results for practical engineering application are drawn.

scholarly journals Characteristics of Wave Forces on Armor Units of a Submerged Breakwater

1992 ◽  
Vol 8 ◽  
pp. 69-74
Author(s):  
Takayuki Nakamura ◽  
Akito Ootsuka ◽  
Takashi Onozuka ◽  
Takahito Mori
Keyword(s):  
Wave Forces ◽  
Submerged Breakwater

Geotechnical sampling in deep water using a tensioned conductor pipe-casing and weighted footblock

1984 ◽  
Vol 21 (1) ◽  
pp. 92-99
Author(s):  
H. T. Yan
Keyword(s):  
Deep Water ◽  
Concrete Block ◽  
Vertical Movement ◽  
The Self ◽  
Wave Forces ◽  
Secondary Effects ◽  
Marine Riser ◽  
Grand Banks ◽  
Riser Pipe ◽  
Axial Tension

A drilling system is described for geotechnical exploration and soil sampling in the seabed, modelled after the concept of the marine riser pipe. The system derives its stability from a "tensioning weight," in the form of a cylindrical concrete block at the bottom, which keeps the conductor pipe in tension at all times. The axial tension from the tensioning weight and the self-weight of the conductor pipe substantially reduce the bending effects in the conductor pipe resulting from current and wave forces, as well as from the drift of the drilling vessel. The lateral reaction required to keep the pipe in place at the sea floor is provided by a concrete footblock. The bottom end of the conductor pipe slides into the footblock, which has a doughnut-shaped cross section that allows for the vertical movement or heave of the drilling vessel. The Hermitian equation is used to solve for the secondary effects due to the deformation of the flexible conductor under wave or current forces and the self-weight of the conductor pipe. The system has been used successfully on the Grand Banks in 122 m of water. Keywords: geotechnical exploration, sampling, deep water drilling, marine riser analogy, tensioning weight.

scholarly journals WAVE RUN-UP OBSERVATIONS ON REVETMENTS WITH DIFFERENT POROSITIES

2012 ◽  
Vol 1 (33) ◽  
pp. 73 ◽  
Author(s):  
Stefan Schimmels ◽  
Michalis Vousdoukas ◽  
Dagmara Wziatek ◽  
Katharina Becker ◽  
Fabian Gier ◽  
...  
Keyword(s):  
Data Analysis ◽  
Concrete Block ◽  
Video Data ◽  
Coastal Protection ◽  
Large Wave ◽  
Wave Flume ◽  
New Type ◽  
Run Up ◽  
Highly Porous ◽  
Good Agreement

Wave run-up plays an important role in the design of coastal protection structures. However, none of the existing formulae for wave run-up predictions explicitly considers the effect of revetment porosity. Recently, two revetments have been tested in the Large Wave Flume (GWK) of Forschungszentrum Küste (FZK), a new type of highly porous polyurethane bonded (PBA revetment) revetment and a smooth interlocked pattern placed concrete block revetment (IPPB revetment), which is considered as “weakly permeable” for the present study. Wave run-up is evaluated by video data analysis based on timestack image processing. The results derived from the timestacks are compared to run-up data measured with conventional wire gauges and the good agreement demonstrates the accuracy and reliability of the video data analysis. The effect of the porosity of the revetment is incorporated into the EuroTop wave run-up formula, showing that for the present case it may reduce the relative run-up heights Ru,2%/Hm0 by about 25 % to 50 % as compared to a smooth impermeable slope.

scholarly journals Numerical Modeling of Failure Mechanisms in Articulated Concrete Block Mattress as a Sustainable Coastal Protection Structure

2021 ◽  
Vol 13 (22) ◽  
pp. 12794
Author(s):  
Ramin Safari Ghaleh ◽  
Omid Aminoroayaie Yamini ◽  
S. Hooman Mousavi ◽  
Mohammad Reza Kavianpour
Keyword(s):  
Numerical Modeling ◽  
Concrete Block ◽  
Breaking Waves ◽  
Physical Models ◽  
Coastal Protection ◽  
Similarity Parameter ◽  
Environmental Friendliness ◽  
Shoreline Protection ◽  
Concrete Blocks ◽  
Run Up

Shoreline protection remains a global priority. Typically, coastal areas are protected by armoring them with hard, non-native, and non-sustainable materials such as limestone. To increase the execution speed and environmental friendliness and reduce the weight of individual concrete blocks and reinforcements, concrete blocks can be designed and implemented as Articulated Concrete Block Mattress (ACB Mat). These structures act as an integral part and can be used as a revetment on the breakwater body or shoreline protection. Physical models are one of the key tools for estimating and investigating the phenomena in coastal structures. However, it does have limitations and obstacles; consequently, in this study, numerical modeling of waves on these structures has been utilized to simulate wave propagation on the breakwater, via Flow-3D software with VOF. Among the factors affecting the instability of ACB Mat are breaking waves as well as the shaking of the revetment and the displacement of the armor due to the uplift force resulting from the failure. The most important purpose of the present study is to investigate the ability of numerical Flow-3D model to simulate hydrodynamic parameters in coastal revetment. The run-up values of the waves on the concrete block armoring will multiply with increasing break parameter (0.5<ξm−1,0<3.3) due to the existence of plunging waves until it (Ru2%Hm0=1.6) reaches maximum. Hence, by increasing the breaker parameter and changing breaking waves (ξm−1,0>3.3) type to collapsing waves/surging waves, the trend of relative wave run-up changes on concrete block revetment increases gradually. By increasing the breaker index (surf similarity parameter) in the case of plunging waves (0.5<ξm−1,0<3.3), the low values on the relative wave run-down are greatly reduced. Additionally, in the transition region, the change of breaking waves from plunging waves to collapsing/surging (3.3<ξm−1,0<5.0), the relative run-down process occurs with less intensity.

scholarly journals The Submerged Breakwater as Prototype of Coastal Protection in Gili Trawangan, Lombok, Indonesia

2015 ◽  
Vol 125 ◽  
pp. 284-290
Author(s):  
Eko Pradjoko ◽  
Imam Bachtiar ◽  
Nanang Matalatta ◽  
Gatot Sugihartono
Keyword(s):  
Coastal Protection ◽  
Submerged Breakwater
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