Said Alhaddad, Andrew Snyder, Sterre V. Bult, Geert Keetels
{"title":"Experimental investigation of cohesive soil erosion caused by translating submerged inclined water jets","authors":"Said Alhaddad, Andrew Snyder, Sterre V. Bult, Geert Keetels","doi":"10.1016/j.apor.2025.104486","DOIUrl":"10.1016/j.apor.2025.104486","url":null,"abstract":"<div><div>Very limited research has been carried out to investigate sediment erosion caused by subaqueous inclined water jets, despite the fact that such water jets are used in subsea engineering (e.g., dredging, trenching, and deep sea mining). Therefore, we conducted a set of novel small-scale experiments to primarily study the effect of jetting inclination on cohesive sediment erosion. The experimental results reveal that vertical jetting results in the largest cavity depth (or ’erosion depth’), but not in the largest cavity size (sediment production). The erosion depth increases with the jetting angle reaching its maximum at 90° and then begins to decrease with further increase in the jetting angle. The results also indicate that the cavity width (or ’erosion width’) is not necessarily correlated with the impingement region but is instead associated with the erosion-effective jet width—the width of the jet where flow velocities are high enough to penetrate the bed. Analysis of the cavity size showed that the largest sediment production was achieved at a 65° jetting angle among the tested jetting angles (25 °, 45 °, 65 °, 90 °, 115 °, 135 °, and 155 °). The erosion depth was found to be highly proportional to the impingement force exerted by the flow on the clay.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104486"},"PeriodicalIF":4.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural and hydraulic response of emerged low-crested cube-armoured breakwaters","authors":"Yalcin Yuksel , Esin Cevik , Cihan Sahin , Marcel R.A. van Gent , Serhat Gumus , Duygu Issever , Umutcan Inal , Mehmet Utku Ogur","doi":"10.1016/j.apor.2025.104488","DOIUrl":"10.1016/j.apor.2025.104488","url":null,"abstract":"<div><div>In this study, the structural and hydraulic behavior of statically stable emerged low-crested cube-armoured breakwaters were investigated by performing physical model tests. This research considered cube armour layers with irregular placement in a double layer and cube armour layers with a regular placement in a single layer. For the single layer placement, two different packing densities were tested (ψ=0.59 and 0.67) because optimizing the packing density is relevant for the ease of construction, lowering the environmental impact and for the costs of cube armour layers. Low-crested breakwaters with both regular and irregular placements were considered with three different crest widths. The armour stability, wave transmission and wave reflection of emerged type low-crested breakwaters using concrete blocks were investigated experimentally under irregular wave conditions. The results show that for cube-armoured low-crested breakwaters with irregular placement, the cube dimensions can be significantly reduced compared to conventional rubble mound breakwaters with higher crests. The structural stability of low-crested breakwaters with single-layer regular placement showed different responses compared to the irregular two-layer case due to the geometric discontinuity at the intersection of the front slope and crest. Although the regularly placed single armour layer is more stable than the irregularly placed double armour layer with the same packing density (ψ=0.59), damage to the crest is more critical, causing instability of the structure for the single armour layer. For the single-layer regular placement with the smaller packing density (ψ=0.59), damage occurred on the front slope and crest, while for the higher packing density (ψ=0.67) relatively limited damage was observed on the crest only. For the hydraulic behavior of low-crested breakwaters with cube amour layers, the incident wave conditions, the freeboard (R<sub>c</sub>) and crest width (B) are the most important parameters. It is evident that for low-crested breakwaters, the wave transmission increases but the reflection decreases compared to conventional breakwaters with a high crest. Based upon a re-evaluation of expressions given in literature on wave transmission and wave reflection at rubble mound low-crested breakwaters, new formulas for cube-armoured structures have been obtained. Hence, this study provides further information and guidance on applications for engineers and researchers on the structural and hydraulic response of low-crested cube-armoured breakwaters because increasing water levels, wave heights and storm frequencies due to global climate change are driving the need for more resistant coastal structures, adaptation measures and improvements in the design of low-crested breakwaters.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104488"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A pole–residue method for computing the transient hydroelastic responses of VLFSs","authors":"Chongyang Sun , Jinwei Sun , Sau-Lon James Hu","doi":"10.1016/j.apor.2025.104483","DOIUrl":"10.1016/j.apor.2025.104483","url":null,"abstract":"<div><div>Conventional methods for computing hydroelastic responses in very large floating structures (VLFSs) typically involve either frequency domain or time domain approaches. While frequency domain methods are constrained to steady-state responses, time domain methods are generally less efficient. This paper introduces an innovative Laplace domain pole–residue approach to calculate the hydroelastic transient response of a VLFS, incorporating hydroelasticity through a discrete-module-beam-bending model. To implement the proposed method, frequency domain data must first be obtained using a standard hydrodynamic package. Additionally, the method requires expressing both external loadings and system transfer functions in a pole–residue form. Subsequently, the pole–residue form of the response is derived through straightforward pole–residue operations. Once the poles and residues of the response are identified, the response time history can be readily determined. This study specifically concentrates on computing the transient hydroelastic response of a VLFS in calm water conditions subjected to highly irregular loading. In the numerical study, the VLFS is modeled as a continuous shallow-draft flexible box, divided into 8 submodules connected by 7 beams. Frequency-dependent hydrodynamic parameters are calculated by the commercial software SESAM. The heave responses of the first and second submodules under an impact loading are investigated and compared with those obtained by a time-domain method. Numerical studies demonstrate that the proposed pole–residue method surpasses traditional time-domain methods in terms of both efficiency and accuracy.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104483"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pan Zhou , Feng Dai , Ben He , Yi Liu , Shanghui Yang , Mingdong Wei
{"title":"Experimental investigation on the axial static and cyclic response of a single pile in medium-dense sands","authors":"Pan Zhou , Feng Dai , Ben He , Yi Liu , Shanghui Yang , Mingdong Wei","doi":"10.1016/j.apor.2025.104493","DOIUrl":"10.1016/j.apor.2025.104493","url":null,"abstract":"<div><div>Cyclic loads induced by environmental factors such as wind, waves, and currents can lead to degradation in pile performance, affecting settlement accumulation and bearing capacity evolution. This paper presents a comprehensive investigation through model tests focusing on a single pile subjected to static and cyclic loading in medium-dense sands. The influence of installation method, diameter, cyclic load amplitude, and loading frequency on pile response was explored, particularly emphasizing the accumulation pattern of pile head settlement and the evolving laws governing pile shaft and end resistance. The findings illustrate that the radial stress at the pile shaft 400 mm away from the pile end increases to 3.27 times its initial stress after pile jacking. As pile diameter increases, the accumulative settlement rate decreases, highlighting the soil-squeezing effect on cyclic stability. Small cyclic loads gradually densify soil around the pile end, increasing pile end resistance, while larger cyclic loads rapidly reduce both pile end and shaft resistance. Under high-amplitude, low-frequency cyclic loading, the load-settlement hysteresis characteristics of model piles intensify, with the hysteresis loops moving more rapidly in the deformation direction.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104493"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Calculation model for lateral response of piles considering the characteristics of sand convection under asymmetric cyclic loading","authors":"Fanhuan Zeng, Chong Jiang","doi":"10.1016/j.apor.2025.104491","DOIUrl":"10.1016/j.apor.2025.104491","url":null,"abstract":"<div><div>Pile foundations supporting wind turbines and offshore platforms are always subjected to asymmetric lateral cyclic loads from wind and waves. To calculate the lateral response of the pile in sand under asymmetric cyclic loading, this paper proposes a <span><math><mrow><mi>p</mi><mo>−</mo><mi>y</mi></mrow></math></span> curve model to deal with different levels of load reversal. According to the state of the soil around the pile under asymmetric cyclic loading, the scaling factor of the reloading curve is modified. The soil collapse-recompression model is also extended to apply to different cases of asymmetric cyclic loading according to the characteristics of soil convection during asymmetric cyclic loading. By modifying the shape and position of the <span><math><mrow><mi>p</mi><mo>−</mo><mi>y</mi></mrow></math></span> curves to different degrees, the lateral response of the pile under asymmetric cyclic loading can be obtained in combination with the improved finite difference method. The validity of the proposed model is demonstrated by comparing the results with the centrifuge model tests. Then, the pile displacement accumulation, the variation of the bending moment, and the soil resistance under asymmetric cyclic loading, are further discussed.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104491"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Manu K Sajan, Babloo Chaudhary, Akarsh P K, Babita Sah
{"title":"Investigations on the development of hybrid mound breakwaters for tsunami defense","authors":"Manu K Sajan, Babloo Chaudhary, Akarsh P K, Babita Sah","doi":"10.1016/j.apor.2025.104489","DOIUrl":"10.1016/j.apor.2025.104489","url":null,"abstract":"<div><div>Tsunamis significantly damage coastal infrastructure and lives, resulting in extensive economic implications. Despite the global adoption of breakwaters as a primary coastal defence measure, it was observed that the structural integrity of several of these breakwaters was compromised during past tsunamis. The present study addresses these vulnerabilities of breakwaters by particularly focusing on the most commonly adopted rubble mound type breakwater. Further, this study introduces a novel technique in order to enhance the reliability of these structures by mitigating the tsunami induced failure mechanisms. In the novel technique, wrap-faced geogrids are implemented to reinforce the rubble mound without compromising the breakwater functionality in dissipating the incident wave energy through transmission. A comprehensive evaluation was carried out, including tsunami overflow tests, analytical assessments, and numerical simulations, to ascertain the effectiveness of the novel hybrid mound breakwater. The findings indicate that the developed hybrid mound breakwater withstood level 1 tsunamis with a 96.7 % reduction in settlement. One of the critical failure mechanism of breakwaters observed during past tsunamis was due to the seepage induced scouring of the foundation. The hybrid mound breakwater showcased a 42.37 % reduction in the foundation pore water pressure during tsunami by incorporating cut off walls. The numerical simulations also reconfirmed the enhanced performance of hybrid mound breakwater to protect the coasts from future tsunamis.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104489"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rainbow reflection of linear long waves excited by a finite graded array of trapezoidal bars","authors":"Jian-Jian Xie , Qing Ye , Huan-Wen Liu","doi":"10.1016/j.apor.2025.104472","DOIUrl":"10.1016/j.apor.2025.104472","url":null,"abstract":"<div><div>In this paper, the Bragg reflection and rainbow reflection/trapping of linear long (or shallow-water) waves excited by a finite array of trapezoidal bars are studied from the perspective of Bloch band theory. Firstly, a closed-form solution of the reflection coefficient for wave propagation over a finite non-uniform array of trapezoidal bars is derived. Secondly, the relation between Bloch band gaps modulated by an infinite uniform array of trapezoidal bars and the Bragg reflection excited by the cognate finite array is investigated. It is revealed for the first time that there is a strong positive correlation between the width of the <span><math><mi>n</mi></math></span>th order Bloch band gap and the intensity of the <span><math><mi>n</mi></math></span>th order Bragg resonance. Thirdly, the rainbow reflection of linear long waves excited by a finite graded array of trapezoidal bars is studied, and the arrangement of bar spacing for rainbow reflection over a broad and continuous bandwidth is proposed. In addition, the strength of rainbow reflection can be enhanced by increasing the number of bars and the filling fraction of bars. Finally, for a target frequency range that needs to be blocked in practical applications, the Bloch band structures could be applied to guide the layout of bars for rainbow reflection.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104472"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of oil spill cleanup strategy on the transport and fate of oil spilled in the Penglai 19–3 oil spill accident","authors":"Lei Qin , Zhixuan Luo , Daosheng Wang , Lin Mu","doi":"10.1016/j.apor.2025.104484","DOIUrl":"10.1016/j.apor.2025.104484","url":null,"abstract":"<div><div>Oil spills can result in significant economic loss, environmental contamination, and hazards to human safety. Although oil spill cleanup efforts are crucial for mitigating these impacts, the quantitative effectiveness of such strategies remains uncertain. This study utilised a three-dimensional underwater oil spill model to assess the impact of cleanup strategies on the transport and fate of oil spilled during the Penglai 19–3 oil spill accident. The wind drift coefficient was calibrated to an optimal value of 0.6 % using satellite remote-sensing data to track oil slicks on the sea surface, and the simulation start time of the accident was determined. The validated model was then used to simulate the Penglai 19–3 oil spill. Sensitivity experiments revealed that delaying the removal of a fixed area of surface oil resulted in an average increase of 6.88 % (0.96 %) in the final oil spill polluted volume (polluted area on the sea surface). Furthermore, cleaning up the entire surface oil a day earlier improved the cleanup efficiency by an average of 52.83 % (48.25 %) in terms of the final oil spill polluted volume (polluted area on the sea surface). The study has provided a quantitative assessment of the effectiveness of oil spill cleanup strategies and emphasised the importance of rapid emergency response to oil spills. It would provide guidance for offshore cleanup operations.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104484"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ammar Ahmed , Ali Azam , Zutao Zhang , Minyi Yi , Touqeer Aslam , Shoukat Ali Mugheri , Daning Hao , Mansour Abdelrahman , Alaeldin M. Tairab
{"title":"An isomorphic Froude scaling approach to bulbous-bottomed buoys in wave energy converters for smart floating cities","authors":"Ammar Ahmed , Ali Azam , Zutao Zhang , Minyi Yi , Touqeer Aslam , Shoukat Ali Mugheri , Daning Hao , Mansour Abdelrahman , Alaeldin M. Tairab","doi":"10.1016/j.apor.2025.104485","DOIUrl":"10.1016/j.apor.2025.104485","url":null,"abstract":"<div><div>Testing full-scale point absorber buoys with enhanced power absorption is challenging and crucial to improving their viability for applications in smart floating cities and marine infrastructure. Bulbous-bottomed (BB) buoys are efficient in hydrodynamics and power absorption for point absorber wave energy converters (PA-WEC). Their experimental validation demands adaptable scaling algorithms to facilitate model-scale tests. This study utilizes a state-of-the-art theoretical algorithm by combining Froude scaling with an isomorphic buoy design approach, facilitating model-scale tests to investigate whether the BB buoys would equally be efficient compared to the reference hemispherical-bottomed (C<img>HS) buoy when deployed and tested experimentally under identical conditions. Additively manufactured scaled buoy models were tested in a laboratory-scale wave flume in both regular waves (inside and outside resonance) and irregular waves, followed by a similarity analysis for performance prediction on the prototype scale. A feasibility study was also established to justify the BB buoy application in real-time PA-WECs. The BB buoys outperformed the C<img>HS buoys within and without resonance in regular and irregular waves, justifying that they can replace them for good. Under the same deployment and test settings, the model-scale BB buoy exhibited a 20<span><math><mo>−</mo></math></span>27 % greater heave motion than the reference without resonance. A full-scale BB buoy could absorb significantly greater wave power than the reference. The case study showed that a C<img>HS-to-BB transition resulted in a 35 % rise in the capture width ratio of a WEC. The WEC, combined with a 5G-IoT and LSTM network, could facilitate self-powered and self-sensing marine applications in a smart floating city.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104485"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dongxi Liu , Qiyang Cai , Yiran Li , Yudi He , Jin Wang
{"title":"Experimental study of primary- and higher-mode resonant sloshing in a horizontally excited square-base tank","authors":"Dongxi Liu , Qiyang Cai , Yiran Li , Yudi He , Jin Wang","doi":"10.1016/j.apor.2025.104482","DOIUrl":"10.1016/j.apor.2025.104482","url":null,"abstract":"<div><div>This study experimentally investigates primary- and higher-mode resonant sloshing induced by horizontal excitations in a square-base tank with finite depth. Due to the equal length and width of the three-dimensional rectangular tank, two predominant sloshing modes (the transverse mode and longitudinal mode) emerge simultaneously, even when the tank is subjected to unidirectional external excitation. Consequently, direct excitation of one mode leads to indirect excitation of the other through nonlinear coupling, a complex phenomenon known as autoparametric interaction. This phenomenon is widely observed in (<em>i, j</em>) sloshing modes, where <em>i</em> ≠ <em>j</em>. However, the coupling of autoparametric interaction is stable only in the lowest mode, higher modes are found to be unstable. The experiment also reveals that when the natural frequencies of two modes are very close, applying external excitation at one natural frequency causes a shift in the dominant frequency towards the natural frequency of the other mode. In summary, the findings of this study highlight that liquid sloshing in a square-base tank involves more complex physics compared to sloshing in a two-dimensional rectangular tank.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104482"},"PeriodicalIF":4.3,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}