Editorial

3 pages, 205 KiB

Open AccessEditorial

Breakwater Behaviour

by María Clavero and M. Esther Gómez-Martín

J. Mar. Sci. Eng. 2023, 11(2), 243; https://doi.org/10.3390/jmse11020243 - 18 Jan 2023

Viewed by 1013

Breakwaters are characteristic maritime works and provide basic infrastructure for artificial sea and land areas such as ports [...] Full article

(This article belongs to the Special Issue Breakwater Behaviour)

Research

Jump to: Editorial, Review

37 pages, 27224 KiB

Open AccessArticle

Physical Mechanism for Seabed Scouring around a Breakwater—A Case Study in Mailiao Port

by I-Fan Tseng, Chih-Hung Hsu, Po-Hung Yeh and Ting-Chieh Lin

J. Mar. Sci. Eng. 2022, 10(10), 1386; https://doi.org/10.3390/jmse10101386 - 27 Sep 2022

Cited by 3 | Viewed by 1797

Abstract

According to a field survey in 2012, the bathymetry near Mailiao Port, located in central Taiwan’s west coast, has a scouring hole that extends approximately 500 m × 100 m with a maximum scour depth of 26 m (eroded from its design depth [...] Read more.

According to a field survey in 2012, the bathymetry near Mailiao Port, located in central Taiwan’s west coast, has a scouring hole that extends approximately 500 m × 100 m with a maximum scour depth of 26 m (eroded from its design depth −22 m to −48 m). To investigate the scour mechanism near the breakwater head and prevent the breakwater from collapsing, this study conducts comprehensive analysis by analyzing field observed data, performing hydraulic model tests, and conducting numerical modeling for the area near the Mailiao Port. The results show that the current plays an important role in the scour process. The physical model tests and numerical simulations both can reproduce the scour phenomenon of the study site. By analyzing field observed data we validated through physical and numerical models. This study concludes that the current caused by the ebb and flood tide, as well as the steep and shallow seabed topography, together comprise the seabed scour mechanism near the Mailiao Port breakwater head. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

17 pages, 6394 KiB

Open AccessArticle

Tidal Bore Scour around a Spur Dike

by Dongzi Pan and Ying Li

J. Mar. Sci. Eng. 2022, 10(8), 1086; https://doi.org/10.3390/jmse10081086 - 08 Aug 2022

Cited by 3 | Viewed by 1747

Abstract

Tidal bores are a natural phenomenon with high flow velocity and destructive potential. A spur dike is a widely used river regulation and embankment protection structure that minimizes erosion, promotes deposition, and protects riverbanks. However, the scouring mechanism around a spur dike under [...] Read more.

Tidal bores are a natural phenomenon with high flow velocity and destructive potential. A spur dike is a widely used river regulation and embankment protection structure that minimizes erosion, promotes deposition, and protects riverbanks. However, the scouring mechanism around a spur dike under the action of a tidal bore is not fully understood, and accurately estimating the maximum scour depth has always been a challenge, limiting the construction and maintenance of spur dikes in estuarine and marine environments. This study analyzed the scouring characteristics around a spur dike induced by tidal bores via field observation and model experiments. The results show that the scours around a spur dike can be divided into dike head scour and upstream side scour. The scour depth is related to the geometric shape of the spur dike and its surrounding riverbed, hydrodynamic forces, and sediment characteristics. The least squares method obtained the fitting formulas for the depth of the scour at the dike head and upstream side. Overall, the present study indicates an agreement of the scouring characteristics around a spur dike between the field observations and laboratory experiment, and the fitting formulas can be effectively applied to engineering practices of a macro-tidal estuary. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

12 pages, 2185 KiB

Open AccessArticle

Load Resistance Factor for Vertical Caisson Breakwater in Korea

by Il-Geun Lee and Dong-Hyawn Kim

J. Mar. Sci. Eng. 2022, 10(4), 468; https://doi.org/10.3390/jmse10040468 - 26 Mar 2022

Cited by 4 | Viewed by 1722

Abstract

The load resistance factor according to the target reliability level was proposed using 16 vertical breakwaters constructed along the coast of Korea. Limit state functions for sliding and overturning limit states were defined. Reliability analysis was performed to obtain the sensitivity of the [...] Read more.

The load resistance factor according to the target reliability level was proposed using 16 vertical breakwaters constructed along the coast of Korea. Limit state functions for sliding and overturning limit states were defined. Reliability analysis was performed to obtain the sensitivity of the limit state function to the design variables. The partial safety factors of the design variable were obtained using the sensitivity, and the load resistance factor was calculated in turn. The representative value of load resistance factors was obtained by optimizing the load resistance factors for 16 vertical breakwaters, and it was verified that the breakwater designed using the representative value had a reliability index greater than the target value. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

19 pages, 90938 KiB

Open AccessArticle

Physical and Numerical Investigations on Wave Run-Up and Dissipation under Breakwater with Fence Revetment

by Enjin Zhao, Lin Mu, Zhaoyang Hu, Xinqiang Wang, Junkai Sun and Zhiyong Zhang

J. Mar. Sci. Eng. 2021, 9(12), 1355; https://doi.org/10.3390/jmse9121355 - 01 Dec 2021

Cited by 3 | Viewed by 2314

Abstract

Revetment elements and protective facilities on a breakwater can effectively weaken the impact of waves. In order to resist storm surges, there is a plan to build a breakwater on the northern shore of Meizhou Bay in Putian City, China. To better design [...] Read more.

Revetment elements and protective facilities on a breakwater can effectively weaken the impact of waves. In order to resist storm surges, there is a plan to build a breakwater on the northern shore of Meizhou Bay in Putian City, China. To better design it, considering different environmental conditions, physical and numerical experiments were carried out to accurately study the effects of the breakwater and its auxiliary structures on wave propagation. In the experiments, the influence of the wave type, initial water depth, and the structure of the fence plate are considered. The wave run-up and dissipation, the wave overtopping volume, and the structure stability are analyzed. The results indicate that the breakwater can effectively resist the wave impact, reduce the wave run-up and overtopping, and protect the rear buildings. In addition, under the same still water depth and significant wave height, the amount of overtopped water under regular waves is larger than that under irregular waves. With the increase of the still water depth and significant wave height, the overtopped water increases, which means that when the storm surge occurs, damage on the breakwater under the high tide level is greater than that under the low tide level. Besides, the fence plate can effectively dissipate energy and reduce the overtopping volume by generating eddy current in the cavity. Considering the stability and the energy dissipation capacity of the fence plate, it is suggested that a gap ratio of 50% is reasonable. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

20 pages, 5320 KiB

Open AccessArticle

Armor Damage of Overtopped Mound Breakwaters in Depth-Limited Breaking Wave Conditions

by Patricia Mares-Nasarre, Gloria Argente, M. Esther Gómez-Martín and Josep R. Medina

J. Mar. Sci. Eng. 2021, 9(9), 952; https://doi.org/10.3390/jmse9090952 - 01 Sep 2021

Cited by 6 | Viewed by 2569

Abstract

Armor damage due to wave attack is the principal failure mode to be considered when designing conventional mound breakwaters. Armor layers of mound breakwaters are typically designed using formulas in the literature for non-overtopped mound breakwaters in non-breaking wave conditions, although overtopped mound [...] Read more.

Armor damage due to wave attack is the principal failure mode to be considered when designing conventional mound breakwaters. Armor layers of mound breakwaters are typically designed using formulas in the literature for non-overtopped mound breakwaters in non-breaking wave conditions, although overtopped mound breakwaters in the depth-induced breaking wave zone are common design conditions. In this study, 2D physical tests with an armor slope H/V = 3/2 are analyzed in order to better describe the hydraulic stability of overtopped mound breakwaters with double-layer rock, double-layer randomly-place cube and single-layer Cubipod^® armors in depth-limited breaking wave conditions. Hydraulic stability formulas are derived for each armor section (front slope, crest and rear slope) and each armor layer. The front slope of overtopped double-layer rock structures is more stable than the front slope of non-overtopped mound breakwaters in breaking wave conditions. When wave attack increases, armor damage appears first on the front slope, later on the crest and, finally, on the rear side. However, once the damage begins on the crest and rear side, the progression is much faster than on the front slope, because more wave energy is dissipated through the armored crest and rear side. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

29 pages, 9261 KiB

Open AccessArticle

Numerical and Physical Modelling of Wave Overtopping on a Smooth Impermeable Dike with Promenade under Strong Incident Waves

by Maria Graça Neves, Eric Didier, Moisés Brito and María Clavero

J. Mar. Sci. Eng. 2021, 9(8), 865; https://doi.org/10.3390/jmse9080865 - 12 Aug 2021

Cited by 9 | Viewed by 2380

Abstract

This paper presents a study of run-up/overtopping over a smooth impermeable dike with promenade using 2D and 3D mesh-based and mesh-free numerical models and results from 2D physical modelling for strong energetic incident waves. These waves induce plunging wave breaking and a complex [...] Read more.

This paper presents a study of run-up/overtopping over a smooth impermeable dike with promenade using 2D and 3D mesh-based and mesh-free numerical models and results from 2D physical modelling for strong energetic incident waves. These waves induce plunging wave breaking and a complex water/air mixture turbulent flow before overtopped the dike, a challenging configuration for numerical models. The analysis is structured in two phases: (i) evaluates the results of 2D numerical and physical models for run-up and overtopping; (ii) compares qualitatively the results of 3D numerical models for overtopping over a dike with promenade between groins located in front of a slope beach. The results indicate that the main differences obtained in run-up and overtopping are due to differences in wave generation and active absorption systems used in physical and numerical models and in turbulent models used by the numerical models. These differences lead to changes on incident wave height and on wave breaking and, consequently, on reflection, run-up and overtopping over the structure. For 3D simulation, even if larger discrepancies were found on overtopping along the dike, mean wave overtopping discharge and water flow height at the crest of the groin head show a similar order of magnitude. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

22 pages, 23302 KiB

Open AccessArticle

Numerical Model Study of Prototype Drop Tests on Cube and Cubipod^® Concrete Armor Units Using the Combined Finite–Discrete Element Method

by Giulio Scaravaglione, John-Paul Latham and Jiansheng Xiang

J. Mar. Sci. Eng. 2021, 9(5), 460; https://doi.org/10.3390/jmse9050460 - 23 Apr 2021

Cited by 4 | Viewed by 3209

Abstract

This paper aims to evaluate the structural strength of unreinforced concrete armor units (CAU), named Cubipod^®, used on rubble-mound breakwaters and coastal structures, through a numerical methodology using the combined finite–discrete element method (FDEM). A numerical modeling methodology is developed to [...] Read more.

This paper aims to evaluate the structural strength of unreinforced concrete armor units (CAU), named Cubipod^®, used on rubble-mound breakwaters and coastal structures, through a numerical methodology using the combined finite–discrete element method (FDEM). A numerical modeling methodology is developed to reproduce the results of an experimental examination published by Medina et al. (2011) of a free-fall drop test performed on a 15 t conventional Cubic block and a 16 t Cubipod^® unit. The field results of the Cube drop tests were used to calibrate the model. The numerically simulated response to the Cubipod^® test is then discussed in the context of a validation study. The calibration process and validation study provide insights into the sensitivity of breakage to tensile strength and collision angle, as well as a better understanding of the crushing and cracking damage of this unit under drop test impact conditions. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

18 pages, 14121 KiB

Open AccessArticle

Virtual Level Analysis Applied to Wave Flume Experiments: The Case of Waves-Cubipod Homogeneous Low-Crested Structure Interaction

by Mireille Escudero, Jassiel V. Hernández-Fontes, Irving D. Hernández and Edgar Mendoza

J. Mar. Sci. Eng. 2021, 9(2), 230; https://doi.org/10.3390/jmse9020230 - 22 Feb 2021

Cited by 5 | Viewed by 2095

Abstract

This paper presents the use of virtual level (VL) probes as an alternative image-based approach to investigate the interaction of waves with coastal structures in wave flume experiments. These probes are defined as regions of interest located at specific positions along the horizontal [...] Read more.

This paper presents the use of virtual level (VL) probes as an alternative image-based approach to investigate the interaction of waves with coastal structures in wave flume experiments. These probes are defined as regions of interest located at specific positions along the horizontal domain of the images, in which edge interfaces are detected and, thus, their vertical motions can be obtained. To demonstrate the use of the methodology, a critical condition of breaking waves interacting with a Cubipod homogeneous low-crested structure (HLCS) in a two-dimensional framework was selected. With the video recorded from the experiments, image calibration, processing, and analysis stages were implemented to analyze the performance of the HLCS in reducing wave elevations and to study the stability of the armor units. The present approach can be extended to a wide range of coastal structures applications where the interface detection between components of the scene is useful to observe the behavior of coastal structures, increasing effectiveness and alternatives to acquire precise data in 2D experimental tests. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

18 pages, 35087 KiB

Open AccessArticle

Assessment of the Performance of an Artificial Reef Made of Modular Elements through Small Scale Experiments

by Dea Cardenas-Rojas, Edgar Mendoza, Mireille Escudero and Manuel Verduzco-Zapata

J. Mar. Sci. Eng. 2021, 9(2), 130; https://doi.org/10.3390/jmse9020130 - 28 Jan 2021

Cited by 8 | Viewed by 5458

Abstract

Artificial reefs have proven to be an optimal and effective solution in stabilizing coastlines around the world. They are submerged structures that imitate the protection service provided by natural reefs accomplishing the functions of dissipating wave energy and protecting beach morphology, but also [...] Read more.

Artificial reefs have proven to be an optimal and effective solution in stabilizing coastlines around the world. They are submerged structures that imitate the protection service provided by natural reefs accomplishing the functions of dissipating wave energy and protecting beach morphology, but also being an ecological solution. In this paper, 2D small-scale experiments were performed to analyze the hydrodynamic, morphological, and ecological behavior of an artificial reef constructed of modular elements. Two typical beach-dune profiles were constructed in a wave flume over which two locations of an artificial reef were tested. From these tests, transmission coefficients were obtained as well as the beach profile response to the presence of the artificial reef. These results are used to discuss about the hydrodynamic, morphological, and ecological performance of the artificial reef. The proposed artificial reef showed good morphological performance while its hydrodynamic function had limited success. In turn, the ecologic performance was theoretically addressed. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

25 pages, 7198 KiB

Open AccessArticle

Hydrodynamic Efficiency of a Wave Energy Converter in Front of an Orthogonal Breakwater

by Dimitrios N. Konispoliatis and Spyridon A. Mavrakos

J. Mar. Sci. Eng. 2021, 9(1), 94; https://doi.org/10.3390/jmse9010094 - 17 Jan 2021

Cited by 16 | Viewed by 2746

Abstract

In the present study, the hydrodynamic efficiency of a cylindrical wave energy converter (WEC) of vertical symmetry axis and arranged in front of a reflecting orthogonal breakwater is explored. The idea is based on exploiting the anticipated amplification of the scattered and the [...] Read more.

In the present study, the hydrodynamic efficiency of a cylindrical wave energy converter (WEC) of vertical symmetry axis and arranged in front of a reflecting orthogonal breakwater is explored. The idea is based on exploiting the anticipated amplification of the scattered and the reflected wave fields originating from the presence of the vertical walls, towards increasing the WEC’s wave power absorption due to the walls’ wave reflections. Two types of converters are examined, namely the heaving device and the oscillating water column (OWC) device, assuming linear potential theory. The associated diffraction-, motion-, and pressure-radiation problems are solved using axisymmetric eigenfunction expansions for the velocity potential around the WECs by properly accounting for the wave field’s modification due to the walls’ presence. To this end, a theoretical formulation dealing with the evaluation of the converter’s performance is presented accounting for the coupling between the WEC and the reflecting vertical walls. The results depict that the amount of the harvested wave power by the WEC in front of an orthogonal wall is amplified compared to the absorbed wave power by the same WEC in the open sea. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

23 pages, 7623 KiB

Open AccessArticle

Performance of an Array of Oscillating Water Column Devices in Front of a Fixed Vertical Breakwater

by Dimitrios N. Konispoliatis

J. Mar. Sci. Eng. 2020, 8(11), 912; https://doi.org/10.3390/jmse8110912 - 12 Nov 2020

Cited by 15 | Viewed by 2168

Abstract

The present study explores the performance of an array of cylindrical oscillating water column (OWC) devices, having a vertical symmetry axis, placed in front of a bottom seated, surface piercing, vertical breakwater. The main goal of this study is the investigation of a [...] Read more.

The present study explores the performance of an array of cylindrical oscillating water column (OWC) devices, having a vertical symmetry axis, placed in front of a bottom seated, surface piercing, vertical breakwater. The main goal of this study is the investigation of a possible increase in the power efficiency of an OWC array by applying, in the vicinity of the array, a barrier to the wave propagation, aiming at amplifying the scattered and reflected waves originating from the presence of the devices and the wall. To cope with the set goal, a theoretical analysis is presented in the framework of linear potential theory, based on the solution of the proper diffraction, and pressure-radiation problems in the frequency domain, using the image theory, the matched axisymmetric eigenfunction expansion formulation, and the multiple scattering approach. Numerical results are presented and discussed in terms of the expected power absorption by the OWCs comparing different array’s characteristics i.e.,: (a) angle of incidence of the incoming wave train; (b) distances from the breakwater; and (c) geometric characteristics of the different arrangements. The results show that compared to the isolated OWC array (i.e., no presence of the wall), the power efficiency of the OWCs in front of a breakwater is amplified at specific frequency ranges. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

Review

Jump to: Editorial, Research

52 pages, 24511 KiB

Open AccessReview

Review on Fixed and Floating Offshore Structures. Part I: Types of Platforms with Some Applications

by Chiemela Victor Amaechi, Ahmed Reda, Harrison Obed Butler, Idris Ahmed Ja’e and Chen An

J. Mar. Sci. Eng. 2022, 10(8), 1074; https://doi.org/10.3390/jmse10081074 - 05 Aug 2022

Cited by 22 | Viewed by 15261

Abstract

Diverse forms of offshore oil and gas structures are utilized for a wide range of purposes and in varying water depths. They are designed for unique environments and water depths around the world. The applications of these offshore structures require different activities for [...] Read more.

Diverse forms of offshore oil and gas structures are utilized for a wide range of purposes and in varying water depths. They are designed for unique environments and water depths around the world. The applications of these offshore structures require different activities for proper equipment selection, design of platform types, and drilling/production methods. This paper will provide a general overview of these operations as well as the platform classifications. In this paper, a comprehensive review is conducted on different offshore petroleum structures. This study examines the fundamentals of all types of offshore structures (fixed and floating), as well as the applications of these concepts for oil exploration and production. The study also presents various design parameters for state-of-the-art offshore platforms and achievements made in the industry. Finally, suitable types of offshore platforms for various water depths are offered for long-term operations. An extension of this study (Part II) covers sustainable design approaches and project management on these structures; this review helps designers in understanding existing offshore structures, and their uniqueness. Hence, the review also serves as a reference data source for designing new offshore platforms and related structures. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

41 pages, 13720 KiB

Open AccessReview

Review on Fixed and Floating Offshore Structures. Part II: Sustainable Design Approaches and Project Management

by Chiemela Victor Amaechi, Ahmed Reda, Harrison Obed Butler, Idris Ahmed Ja’e and Chen An

J. Mar. Sci. Eng. 2022, 10(7), 973; https://doi.org/10.3390/jmse10070973 - 15 Jul 2022

Cited by 11 | Viewed by 10169

Abstract

Offshore structures exist in a variety of forms, and they are used for a variety of functions in varied sea depths. These structures are tailored for certain environments and sea depths. Different actions for suitable equipment selection, platform type design, and drilling/production processes [...] Read more.

Offshore structures exist in a variety of forms, and they are used for a variety of functions in varied sea depths. These structures are tailored for certain environments and sea depths. Different actions for suitable equipment selection, platform type design, and drilling/production processes are required for the applications of these offshore structures, as given in Part I. This paper is the second part, which outlines various processes, loads, design approaches and project management of offshore platforms. To achieve these, proper planning must be conducted for lifting, transportation, installation, design, fabrication, and commissioning of these offshore platforms. Some historical developments of some offshore structures are presented, and some project planning routines are undertaken in this research. The ultimate goal is to provide a general overview of the many processes of offshore platform design, construction, loadout, transportation, and installation. Some discussions on the design parameters such as water depth and environmental conditions were presented. It also lists various software programs used in engineering designs covering software programs for structural analysis, 3D rendering, computer-aided design (CAD), hydrodynamic design, oceanic flow analysis, offshore structures analysis, mathematical modelling, coding/algorithm development software, and programming software to aid analytical calculations. The review also includes information on cutting-edge offshore platforms and industry advancements. Ultimately, for long-term operations, various types of offshore platforms for specific seawater depths are available. Full article

(This article belongs to the Special Issue Breakwater Behaviour)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Breakwater Behaviour

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Related Special Issue

Published Papers (14 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI