The planning and management of coastal and river structures such as breakwaters, groynes, jetties, bridges and tidal inlets require accurate predictions of equilibrium morphologies. Generally these types of situations are modelled numerically using process - based models, where wave, current and sediment transport modules are applied over a number of time - steps until a steady - state morphology is obtained. Two alternative methods have been developed and applied in this thesis, based on self - organisation and entropy approaches. The self - organisation - based method utilises a cellular automata model, where local rules produce a global stable pattern through positive and negative feedback. The entropy - based method is able to predict equilibrium morphologies directly. It compares different randomly generated morphologies using an objective function and optimisation, instead of moving to an equilibrium morphology through intermediate states. This avoids some potential problems associated with traditional models such as error propagation and reliance on accurate initial conditions. The models developed in this thesis have been applied to a number of case studies. It was found that the cellular automata model obtained a higher Brier Skill Score than a comparable process - based model when predicting the equilibrium morphology associated with a channel obstruction. The entropy - based method was able to predict a realistic erosional channel in a coastal lagoon, similar to field observations at the Murray River Mouth in South Australia. It had difficulties predicting the deposition pattern due to the bias of the objective function towards erosional environments. The entropy - based method outperformed a conventional model prediction of the equilibrium erosional channel associated with a laboratory - sized lagoon, but similar problems were observed with its deposition predictive ability. The modelling methods developed in this thesis are a first step into the use of non - traditional, entropy - and self - organisation - based models for the prediction of complex equilibrium morphologies. They have made use of non - conventional models in order to explore different objective function formulations or self - organisation rules and the sensitivity of these, and have compared the models to laboratory results. The work documented in this dissertation shows that it is possible to use self - organisation - and entropy - based modelling methods to predict stable, equilibrium morphologies in coastal and river environments. / Thesis (Ph.D.)--School of Civil and Environmental Engineering, 2006.

Orientador: Tiago Zenker Gireli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-20T11:55:27Z (GMT). No. of bitstreams: 1 Vieira_LuanaKannKelch_M.pdf: 9568135 bytes, checksum: e1cf844235f741c2950c6e1ecba0b1ed (MD5) Previous issue date: 2012 / Resumo: O desenvolvimento econômico brasileiro tem gerado a necessidade de melhoria no transporte e logística dos produtos que circulam pelo país. O transporte marítimo é a opção menos poluente e menos custosa para o transporte de mercadorias. Com o aumento da demanda neste segmento surge o interesse por alternativas ecológicas e economicamente mais atrativas. Como parte integrante do projeto de um terminal portuário, obras de abrigo são necessárias na grande maioria dos casos. Nesse contexto, foi resgatada a importância da pesquisa e inovação do quebra-mar flutuante. Além disso, o quebra-mar também pode promover proteção costeira, outra discussão muito atual. O quebra-mar desenvolvido e estudado nesse trabalho é uma inovação e possui vantagens dentre as concepções praticadas atualmente. O conceito ecológico de empregar garrafas PET descartadas, eliminando-as do ambiente, cria um interesse ímpar por parte dos ambientalistas. Economicamente esse quebra-mar é mais vantajoso, pois os materiais são de baixo custo e de fácil aquisição. E também pode ser construído em terra e rebocado para a posição, no corpo d'água, eliminando as dificuldades e custos de uma construção a partir de plataformas destacadas e flutuantes. Por último, ressalta-se a eficiência na redução da altura de onda, pois esta foi significativamente maior que a encontrada por pesquisadores que testaram concepções comparáveis a essa / Abstract: The growth of the Brazilian economy urges for improvement in transportation and logistics for products that move though the country. Seaways are the less pollutant and the most cost effective way to move ware. The increasing demand for this segment creates interest in more environmentally friendly and cheaper options and sheltering installations are part of a port's design. Within this scenario, the relevance of research and innovation for floating breakwater is recovered. Furthermore breakwater can as well provide coastal protection, which is an existent concern in modern time. The floating breakwater that is being discussed in this paper is an innovative and advantageous when compared to others that are in use have been designed and built. Due to the reuse of many plastic bottles and regarding the fact that they are being taken away from the waste environment, this floating breakwater creates a good impact on the ecologists. From the economic point of view it is less expensive due to the fact of the purchase of used plastic bottles to be cheap and easy. Also, the breakwater can be constructed on shore and dragged to position which eliminates the complexity and coast of building of a vessel. Its efficiency in wave height reduction goes significantly beyond the reduction ratio of other concepts that are comparable to this floating breakwater / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil

The nature of British Columbia coastal and inland waterways affords many locations where floating breakwaters are or could be used to protect small-craft harbours from wave action. A field survey of many of the current breakwater sites is undertaken in order to establish qualitative performance criteria of various designs. A two-dimensional numerical model is developed to predict the oscillatory response and wave transmission characteristics for a number of common breakwater designs. Finally, experiments with two configurations of breakwater models were carried out in the Hydraulics Laboratory at the University of British Columbia. The experiments were designed to validate the numerical model and to estimate viscous damping coefficients required in the numerical solution. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Oyster reefs provide valuable ecosystemservices that contribute to coastal resilience. Unfortunately, many reefs have been degraded or removed completely, and there are increased efforts to restore oysters in many coastal areas. In particular, much attention has recently been given to the restoration of shellfish reefs along eroding shorelines to reduce erosion. Such fringing reef approaches, however, often lack empirical data to identify locations where reefs are most effective in reducing marsh erosion, or fully take into account habitat suitability. Using monitoring data from 5 separate fringing reef projects across coastal Louisiana, we quantify shoreline exposure (fetch + wind direction + wind speed) and reef impacts on shoreline retreat. Our results indicate that fringing oyster reefs have a higher impact on shoreline retreat at higher exposure shorelines. At higher exposures, fringing reefs reduced marsh edge erosion an average of 1.0 m y-1. Using these data, we identify ranges of shoreline exposure values where oyster reefs are most effective at reducing marsh edge erosion and apply this knowledge to a case study within one Louisiana estuary. In Breton Sound estuary, we calculate shoreline exposure at 500 random points and then overlay a habitat suitability index for oysters. This method and the resulting visualization show areas most likely to support sustainable oyster populations as well as significantly reduce shoreline erosion. Our results demonstrate how site selection criteria, which include shoreline exposure and habitat suitability, are critical to ensuring greater positive impacts and longevity of oyster reef restoration projects.

This study investigates the relationship between wave-induced hydrodynamics and the resulting loading on Core-Loc concrete armour units below the still water level in a breakwater structure. Physical modelling experiments were performed at the National Research Council in Ottawa in which a 3D-printed 12 cm Core-Loc armour unit was instrumented and fixed in place within a rubble mound structure. Testing featured simultaneous measurement of force on this instrumented unit, pressure head at the base of the unit, and flow velocities below the SWL. Two main scenarios were tested, the isolated unit and fully armoured scenarios, under a range of regular waves and irregular sea states. Analysis of force development on the instrumented unit indicates that maximum slope-normal forces (both into and away from the structure) are associated with extremes in pressure head above the instrumented unit, while slope-parallel force extremes (both upslope and downslope) occur at times of the fastest change in water level. These loadings are consistent with Morison’s equation and imply drag dominance in the slope-parallel direction and inertia dominance in the slope-normal direction. Significant differences in forces were observed between isolated (no neighbouring units) and embedded (with neighbouring units) armour unit test cases. The presence of the armour layer significantly increased the normal force exerted on the unit and reduced the parallel force. Irregular sea state testing shows force peaks following normal distribution. Analysis of flow above the armour layer showed that force, flow velocity and flow acceleration are symmetrical in the slope-parallel direction, but largely asymmetrical in the slope-normal direction, with the flow velocity and force on the unit in particular experiencing large asymmetries. Wave height analysis indicated that each wave height follows a similar force development pattern with a magnitude proportional to wave height. Wave period analysis showed the formation of small secondary waves as the period increases. Wave steepness affected the peak force loading of the instrumented unit in a mostly linear fashion up to the critical Iribarren number.

An experimental investigation of the interaction of water waves with flexible structures acting as breakwaters was carried out. Wave profiles, mapped out by water level measuring transducers, were studied to provide information on the performance of different breakwater models. A new signal analysis procedure for determining reflection coefficients based on wavelet theory was developed and compared to a conventional method. The reliability of using wavelet analysis to separate a partial standing wave into incident and reflected wave components was verified with a numerical example. It was also verified by the small variance in the estimates of the incident wave height from independent experimental measurements. Different geometries of rigid and flexible structures were constructed and examined. Reflection, transmission and energy loss coefficients were obtained over them. The influence of various properties of the models, such as the width and the internal pressure, on the effectiveness in reflecting or absorbing the incident wave energy was determined. Various factors which affect the performance of the breakwater, including the water depth, the wave length and the wave amplitude, were measured and documented. Suspended and bottom-mounted models were considered. The flow field over and near a hemi-cylindrical breakwater model was also examined using a flow visualization technique. An overall comparison among the models has also been provided. The results showed that the rectangular models, rigid and flexible, are the most effective structures to dissipate wave energy. The flow visualization technique indicated that the flow conforms with the circular geometry of a hemi-cylindrical breakwater model, yielding no flow separation. / Ph. D.

Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: The port of Ngqura is situated on the east coast of South Africa. Since its first operational winter excessive vessel motions have interrupted container shipping operations and lead to mooring line failure. A major component contributing to the excessive motions is the presence of seiching in the port, resonating long waves. This study investigates the long wave generation, penetration into the port and subsequent resonance in the vicinity of the problem berths. An extensive literature review identified two predominant types of long waves along the coast of South Africa. Long waves with periods over 12 min generated by resonant air-water coupling and then shorter long waves between 30 s and 6 min attributed to bound long wave energy and broadly speaking, surf beat. A review of the state of the art long wave modelling techniques was included and contributed to the methodology in this study. Analysis of simultaneous measurements from the outside and inside of the port confirmed the generating mechanism of the long waves to be storm systems also responsible for generating short waves. Long waves outside the port were found to be on average 8% of the height of the short waves. On average 90% of the long wave height outside the port penetrated the port. The measurements further identified distinct resonating periods of the long wave energy inside the port. Calibrated Boussinesq wave models allowed for identification of how long waves penetrated the port and subsequently resonated. Both surface elevation measurements and white noise spectra were used as inputs. The penetration mechanisms were attributed to direct diffraction around the main breakwater as well as reflection off the beach south of the port leading to refraction and reflection off the lee side of the main breakwater. Tests with both free and bound long waves proved that at least for some period intervals the long wave energy was indeed bound to short waves. The excessive vessel motions are attributed to berths positioned in line with nodes created by the resonating long waves; nodes are characterized by strong horizontal currents which can induce surge motions in vessels. Various long waves between the period intervals of 45 s to 125 s resonate in the port to generate nodes at the berths of interest. In conclusion, the port of Ngqura is susceptible to a range of long wave periods resulting in significant basin oscillations which present nodes at mooring places. As a result of the analyses in this study the mechanisms of interaction between the port, port basins and the long waves penetrating into the port directly, or via the surf zone as surf beats, have been modelled, documented and better understood. This provides the potential for better prediction of severe long wave events and for the investigation of feasible mitigation measures to prevent damage to moored ships in the port. / AFRIKAANSE OPSOMMING: Die Ngqura hawe is aan die ooskus van Suid-Afrika geleë. Sedert die hawe se eerste operasionele winterseisoen, het oormatige skeepsbewegings operasies van behoueringskepe onderbreek en gelei tot faling van vasmeertoue. Die teenwoordigheid van langgolf resonansie is ‘n groot bydraende faktor tot die oormatige skeepsbewegings. Hierdie studie ondersoek die opwekking, penetrasie en gevolglike resonansie van langgolwe in die areas aangrensend tot die problematiese kaaie. ‘n Uitgebreide literatuurstudie het twee tipes langgolwe aan die Suid-Afrikaanse kus geïdentifiseer, naamlik langgolwe met periodes langer as 12 minute wat deur resonante lug-water koppeling opgewek word en korter langgolwe met periodes tussen 30 s en 6 min wat aan gebonde langgolfenergie of, meer algemeen, surf beat toegeskryf word. Verder is ‘n studie rakende die jongste langgolfmodelleringstegnieke ook uitgevoer waaruit die metodiek van hierdie studie bepaal is. ‘n Analise van gelyktydige opmetings binne en buite die hawe het bevestig dat kortgolwe wat deur stormsisteme gegenereer word, die opwekkingsmeganisme van lang golwe is. Daar is bevind dat langgolwe buite die hawe gemiddeld 8% so hoog soos kort golwe is. ‘n Gemiddeld van 90% van die langgolfhoogte het die hawe penetreer. Die opmetings het ook verder duidelike resonansieperiodes van langgolfenergie binne die hawe aangedui. Gekalibreerde Boussinsq-golfmodelle is gebruik om te indentifiseer hoe langgolwe die hawe binnedring en gevolglik resoneer. Beide oppervlakmetings en wit geraas spektra is as invoerwaardes vir die model gebruik. Die penetrasiemeganismes is toegeskryf aan diffraksie rondom die hoof hawemuur asook refleksie vanaf die strand, suid van die hawe, wat lei tot refraksie en refleksie teen die lykant van die hoof hawemuur. Toetse met vry langgolwe het bewys dat die langgolfenergie, vir ten minste sommige periode intervalle, aan die kort golwe vebonde is. Die oormatige skeepsbewegings is toegeskryf aan die kaaie wat in lyn met nodes van die langgolfresonansie geposisioneer is. Nodes word gekarakteriseer deur sterk horisontale strome wat surge bewegings in skepe kan veroorsaak. Verskeie langgolwe met periode intervalle tussen 45 s tot 125 s resoneer in die hawe en vorm nodes by die kaaie van belang. Ten slotte, die Ngqura hawe is vatbaar vir ‘n reeks langgolfperiodes wat ossilasies in die bekkens van die hawe veroorsaak en nodes naby kaaie vorm. As gevolg van die analises in hierdie studie is die meganismes van interaksie tussen die hawe, sy bekkens en langgolwe wat die hawe direk of via die brandersone binnedring gemodelleer, gedokumenteer en beter verstaan. Hierdeur is die potensiaal vir beter voorspelling van ernstige langgolftoestande verhoog en is dit moontlik gemaak om lewensvatbare oplossings vir skade aan vasgemeerde skepe te ondersoek.

In this thesis, a new computer model (tool) for the reliability-based design of rubble-mound coastal defense structures is developed in which design is carried out in a user frienly way giving outputs on time variant reliability for the predetermined lifetimes and damage levels. The model aims to perform the following steps: 1. Determine the sources of uncertainties in design parameters 2. Evaluate the damage risk of coastal structures which are at design stage and are recently constructed. 3. Study the sensitivity of limit state functions to the design parameters. Different from other reliability studies on coastal projects, a new design computer program is developed that can be easily used by everyone working in coastal engineering field.

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Sea-level rise due to climate change results in deeper water next to existing coastal structures, which in turn enables higher waves to reach these structures. Wave overtopping occurs when wave action discharges water over the crest of a coastal structure. Therefore, the higher waves reaching existing structures will cause higher wave overtopping rates. One possible solution to address increasing overtopping, is to raise the crest level of existing coastal structures. However, raising the crest level of a seawall at the back of a beach, will possibly obstruct the view to the ocean from inland. Alternatively, recurves can be incorporated into the design of both existing and new seawalls. The recurve wall reduces overtopping by deflecting uprushing water seawards as waves impact with the wall. The main advantage of seawalls with recurves is that their crest height can be lower, but still allow for the same wave overtopping rate as vertical seawalls without recurves. This project investigates the use of recurve seawalls at the back of a beach to reduce overtopping and thereby reducing the required wall height. The objectives of the project are twofold, namely: (1) to compare overtopping rates of a vertical seawall without a recurve and seawalls with recurves; and (2) to determine the influence that the length of the recurve overhang has on the overtopping rates. To achieve these objectives, physical model tests were performed in a glass flume equipped with a piston type wave paddle that is capable of active wave absorption. These tests were performed on three different seawall profiles: the vertical wall and a recurve section with a short and a long seaward overhang, denoted as Recurve 1 and Recurve 2 respectively. Tests were performed with 5 different water-levels, while the wall height, wave height and period, and seabed slope remained constant. Both breaking and non-breaking waves were simulated. A comparison of test results proves that the two recurve seawalls are more effective in reducing overtopping than the vertical seawall. The reduction of overtopping can be as high as 100%, depending on the freeboard and wave conditions. Recurve 2 proves to be the most efficient in reducing overtopping. However, in the case of a high freeboard (low water-level at the toe of the structure), the reduction in overtopping for Recurve 1 and Recurve 2 was almost equally effective. This is because all water from the breaking waves is reflected. Even for the simulated lower relative freeboard cases, the recurve walls offer a significant reduction in overtopping compared with the vertical wall. A graph is presented which shows that the length of the seaward overhang influences the overtopping performance of the seawall. As the seaward overhang length increases, the wave overtopping rate decreases. However, for high freeboard cases the length of the seaward overhang becomes less important. The graph gives designers an indication of how recurves can be designed to reduce seawall height while retaining low overtopping. It is recommended that further model tests be performed for additional overhang lengths. Incorporation of recurves into seawall design represents an adaptation to problems of sea-level rise due to global warming / AFRIKAANSE OPSOMMING: Stygende seevlak as gevolg van klimaatverandering, veroorsaak dat dieper water langs bestaande kusstrukture voorkom. Gevolglik kan hoër golwe hierdie strukture bereik. Golfoorslag vind plaas wanneer water oor die kruin van ‘n kusstruktuur, hoofsaaklik deur golfaksie, spat of vloei. Dus sal hoër golfhoogtes tot verhoogde golfoorslag lei. Een moontlike oplossing vir hierdie verhoogde golfoorslag is om die kruinhoogte van bestaande kusstrukture te verhoog. In die geval van ‘n seemuur aan die agterkant van ‘n strand, kan hoër strukture egter die see-uitsig na die see vanaf die land belemmer. Om hierdie probleem te vermy, kan terugkaatsmure in die ontwerp van bestaande en nuwe seemure ingesluit word. Terugkaatsmure verminder golfoorslag deurdat opspattende water, afkomstig van invallende golwe terug, na die see gekaats word. Die grootste voordeel van ‘n terugkaatsmuur is dat hierdie tipe muur ‘n laer kruinhoogte as die vertikale seemuur sonder ‘n terugkaatsbalk, vir dieselfde golfoorslagtempo kan hê. Hierdie projek ondersoek dus die gebruik van terugkaatsmure aan die agterkant van ‘n strand met die doel om golfoorslag te verminder en sodoende die vereiste muurhoogte te verminder. Die doelwit vir die projek is tweeledig: (1) om die golfoorslagtempo van terugkaatsmure te vergelyk met dié van ‘n vertikale muur sonder ‘n terugkaatsbalk; en (2) om die invloed van die terugkaatsmuur se oorhanglengte op die golfoorslagtempo te bepaal. Om bogenoemde doelwitte te bereik, is fisiese modeltoetse in ‘n golfkanaal, wat met ‘n suiertipe golfopwekker toegerus is en wat aktiewe golfabsorbering toepas, uitgevoer. Hierdie toetse is op drie verskillende seemuurprofiele, naamlik ‘n vertikale muur en ‘n terugkaatsmuur met ‘n kort en lang oorhang, genaamd “Recurve 1” en “Recurve 2” onderskeidelik, uitgevoer. Die muurhoogte, die seebodemhelling asook die golfhoogte en –periode is tydens al die toetse konstant gehou. Vir elke profiel is toetse by 5 verskillende watervlakke vir beide brekende en ongebreekte golwe uitgevoer. Uit die toetsresultate is dit duidelik dat terugkaatsmure meer effektief as vertikale mure is om golfoorslag te beperk. Die vermindering van golfoorslag kan tot 100% wees, afhangende van die vryboord en golftoestande. Daar is bevind dat “Recurve 2” golfoorslag die effektiefste verminder. In die geval van hoë vryboord (lae watervlak by die toon van die struktuur) is daar egter gevind dat “Recurve 1” en “Recurve 2” die golfoorslag feitlik ewe goed beperk. Dit is die geval aangesien alle water van die brekende golwe weerkaats word. In die geval van ‘n lae vryboord, word die voordeel van die terugkaatsmuur teengewerk deurdat daar ‘n kleiner verskil in golfoorslagtempo’s tussen die drie profiele is. ‘n Grafiek is voorgelê wat wys dat die lengte van die terugkaatsmuur se oorhang golfoorslag beperk. ‘n Groter oorhanglengte van die terugslagmuur veroorsaak ‘n groter vermindering in golfoorslag. Vir gevalle met ‘n hoë vryboord, is daar egter gevind dat die oorhanglengte van die terugslagmuur minder belangrik is. Hierdie grafiek gee ontwerpers ‘n aanduiding van hoe terugslagmure ontwerp kan word met ‘n lae hoogte terwyl ‘n lae oorslagtempo behou word. Die gebruik van terugslagmure bied ‘n aanpassing vir die probleme van seevlakstyging, as gevolg van klimaatverandering.

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: For the safekeeping or harbouring of small craft, whether for leisure or commercial use, a tranquil basin is the principle requirement in designing a functional harbour facility. Waves transmitted through the perimeter structures of a marina result in agitation of the basin and thereby a reduction in tranquillity. Similarly, waves reflected off the perimeter structures that line entrance channels could result in difficulty when manoeuvring through the entrance channel water areas. An alternative to the conventional breakwater becomes a necessity when the conventional mass-filled or caisson breakwaters are not feasible in technical or financial terms. One of the alternative options could be to consider a piled row breakwater. In broad terms, this consists of closely spaced piles that attenuate wave energy whilst not forming an impermeable barrier, allowing for currents and sediment to pass through. When comparing the different options for creating a piled row breakwater the quantity of material used to achieve a desired level of wave dissipation could be the most important aspect in considering possible alternatives, as this would relate directly to construction costs and time when considering implementation. A literature review revealed multiple references to theories that predicted the transmitted and reflected waves for various breakwater porosities and wave conditions. However, there is limited coverage in literature enabling prospective designers. For example, literature describing the applicable ranges of shape configurations that one should start off with when developing concepts is not readily available. This thesis study used physical modelling to compare the wave transmission properties of breakwaters comprised of three different piled element shapes, namely round, square and diagonal square piles. The pile element shapes are compared for varying porosity values over a range of input wave parameters. A comparison of the transmission incurred by these configurations with previous work is presented and it was found that the physical model experiment closely simulated the predicted values. The tests were scaled from actual conditions in possible marina locations and therefore the performance criteria measured could be applied in reverse to potential site locations. From analysis of the physical model results, it was clear that the highest energy loss was found, in general, to occur with low porosities (below 10%), as could be expected. For a fixed screen configuration in terms of pile element shape and porosity, the performance is heavily dependent on wave steepness, the steeper waves incurring a lower transmission coefficient than the less steep waves. For a given porosity, circular piles performed the best (transmit the least) followed by square piles and then diagonal square. When comparing the material used, diagonal square piles yielded better performing breakwaters due to the expanded cross section gained in elevation. The work has provided useful insight into the performance of piled row breakwaters in restricting transmission of wave energy. Design guidance has been provided when considering the parameters for deriving conceptual layouts for piled row breakwater structures. Recommendations were put forward for further work in this field, including potential study areas, data gathering, and study methods, as well as more applied uses of piles, for example in combination with other elements in a marina. / AFRIKAANSE OPSOMMING: die veilige bewaring van klein vaartuie, hetsy vir ontspanning of kommersiële gebruik, is die hoofvereiste in die ontwerp van 'n funksionele hawe fasiliteit dat die beskermde hawegebied ‘n rustende water oppervlak sal moet handhaaf. Golwe wat oorgedra word deur die omtrek golfbrekers van ‘n hawe deur middel van transmissie veroorsaak oppervlak versteurings in die hawe bak en dus ook ongewensde versteurings in die vasmeer kondisies. Op ‘n soortgelyke wyse, veroorsaak golwe wat gereflekteer word vanaf die toegangs kanaal golfbrekers problematiese kondisies vir die navigeer van bote deur die kanaal. Die behoefte aan 'n golfbreker alternatief vir die konvensionele oplossing word genoodsaak wanneer die konvensionele stortrots of caisson golfbrekers nie haalbaar is nie as gevolg van tegniese of finansiële aspekte (Park et al. 2000). Een van die opsies wat oorweeg kan word as 'n alternatief is ‘n heipaal-ry tipe breekwater. In breë terme, bestaan dit uit naby gespasieërde heipale om golf energie te breek, sonder om ‘n ondeurdringbare versperring te vorm. Wanneer die verskillende opsies vir die skep van 'n heipaal-ry tipe breekwater vergelyk word, kan die hoeveelheid konstruksie materiaal benodig per opsie die belangrikste vergelykende parameter word. Die rede hiervoor is die direkte verwantskap aan konstruksie kostes sowel as tyd aspekte wat gepaardgaan met die konstruksie materiaal hoeveelhede. Vanuit die literatuurstudie is verskeie verwysings geïdentifiseer waarin vorige teorieë oor oordrag en refleksie van golwe evalueer word vir wisselende porositeit waardes en intree golf waardes. Daar is egter 'n beperkte dekking in die literatuur wat ontwerps-riglyne betref. Byvoorbeeld, die toepaslike omvang van die vorm konfigurasies wat oorweeg moet word wanneer konsep ontwerp gedoen word, is nie geredelik beskikbaar nie. Hierdie tesis vergelyk, deur middel van fisiese skaal model toetse, drie heipaal-ry element vorms, naamlik ronde, vierkantige en diagonal geroteerde vierkante vir verskillende porositeit waardes oor 'n verskeidenheid van golf inset parameters. 'n Vergelyking is getref tussen die toetsdata en vorige werk en daar is bevind dat die fisiese model eksperiment die voorspelde waades uit die literatuur redelik akkuraat kon naboots. Die toets kondisies is geskaal vanaf werklike moontlike marina terreine en dus kon die toets resultate toegepas word in die ontwerp van potensiële terreine. Vanuit die data-analise, is waargeneem dat die hoogste energie verliese oor die algemeen plaasvind by laer porosititeit waardes (onder 10%) soos wat verwag kon word. Vir 'n gegewe golfbreker opset, in terme van die heipaal element vorm en porositeit, is die verrigting hoogs afhanklik van die golf steilheid, met hoër verrigting by steiler golwe. Vir 'n gegewe porositeit, sal ronde heipaal elemente die beste verrigting gee, gevolg deur vierkante heipale en laastens diagonal geroteerde vierkante. Vir soortgelyke hoeveelheid heipale, sal diagonal geroteerde vierkante beter verrigting lewer moontlik as gevolg van die verlengde deursnit dimensie in vooraansig. Hierdie navorsing het goeie insig verskaf oor golfdeurlaatbaarheid en weerkaatsing van heipaalry breekwaters. Ontwerp riglyne word ook verskaf wat betref die parameters wat gebruik kan word vir die konsep ontwikkelings fase vir heipaal-ry breekwaters. Aanbevelings word gemaak vir verdere navorsingswerk in hierdie veld, insluitend moontlike studie-areas, data insameling, studie metodes, sowel as vir meer toegepasde situasies, byvoorbeeld waar die heipaal elemente in kombinasie met ander marina komponente ontwerp moet word.