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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Algorithmic component and system reliability analysis of truss structures

Hashemolhosseini, Sepehr 12 1900 (has links)
Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: Most of the parameters involved in the design and analysis of structures are of stochastic nature. This is, therefore, of paramount importance to be able to perform a fully stochastic analysis of structures both in component and system level to take into account the uncertainties involved in structural analysis and design. To the contrary, in practice, the (computerised) analysis of structures is based on a deterministic analysis which fails to address the randomness of design and analysis parameters. This means that an investigation on the algorithmic methodologies for a component and system reliability analysis can help pave the way towards the implementation of fully stochastic analysis of structures in a computer environment. This study is focused on algorithm development for component and system reliability analysis based on the various proposed methodologies. Truss structures were selected for this purpose due to their simplicity as well as their wide use in the industry. Nevertheless, the algorithms developed in this study can be used for other types of structures such as moment-resisting frames with some simple modi cations. For a component level reliability analysis of structures different methods such as First Order Reliability Methods (FORM) and simulation methods are proposed. However, implementation of these methods for the statistically indeterminate structures is complex due to the implicit relation between the response of the structural system and the load effect. As a result, the algorithm developed for the purpose of component reliability analysis should be based on the concepts of Stochastic Finite Element Methods (SFEM) where a proper link between the finite element analysis of the structure and the reliability analysis methodology is ensured. In this study various algorithms are developed based on the FORM method, Monte Carlo simulation, and the Response Surface Method (RSM). Using the FORM method, two methodologies are considered: one is based on the development of a finite element code where required alterations are made to the FEM code and the other is based on the usage of a commercial FEM package. Different simulation methods are also implemented: Direct Monte Carlo Simulation (DMCS), Latin Hypercube Sampling Monte Carlo (LHCSMC), and Updated Latin Hypercube Sampling Monte Carlo (ULHCSMC). Moreover, RSM is used together with simulation methods. Throughout the thesis, the effciency of these methods was investigated. A Fully Stochastic Finite Element Method (FSFEM) with alterations to the finite element code seems the fastest approach since the linking between the FEM package and reliability analysis is avoided. Simulation methods can also be effectively used for the reliability evaluation where ULHCSMC seemed to be the most efficient method followed by LHCSMC and DMCS. The response surface method is the least straight forward method for an algorithmic component reliability analysis; however, it is useful for the system reliability evaluation. For a system level reliability analysis two methods were considered: the ß-unzipping method and the branch and bound method. The ß-unzipping method is based on a level-wise system reliability evaluation where the structure is modelled at different damaged levels according to its degree of redundancy. In each level, the so-called unzipping intervals are defined for the identification of the critical elements. The branch and bound method is based on the identification of different failure paths of the structure by the expansion of the structural failure tree. The evaluation of the damaged states for both of the methods is the same. Furthermore, both of the methods lead to the development of a parallel-series model for the structural system. The only difference between the two methods is in the search approach used for the failure sequence identification. It was shown that the ß-unzipping method provides a better algorithmic approach for evaluating the system reliability compared to the branch and bound method. Nevertheless, the branch and bound method is a more robust method in the identification of structural failure sequences. One possible way to increase the efficiency of the ß-unzipping method is to define bigger unzipping intervals in each level which can be possible through a computerised analysis. For such an analysis four major modules are required: a general intact structure module, a damaged structure module, a reliability analysis module, and a system reliability module. In this thesis different computer programs were developed for both system and component reliability analysis based on the developed algorithms. The computer programs are presented in the appendices of the thesis. / AFRIKAANSE OPSOMMING: Meeste van die veranderlikes betrokke by die ontwerp en analise van strukture is stogasties in hul aard. Om die onsekerhede betrokke in ontwerp en analise in ag te neem is dit dus van groot belang om 'n ten volle stogastiese analise te kan uitvoer op beide komponent asook stelsel vlak. In teenstelling hiermee is die gerekenariseerde analise van strukture in praktyk gebaseer op deterministiese analise wat nie suksesvol is om die stogastiese aard van ontwerp veranderlikes in ag te neem nie. Dit beteken dat die ondersoek na die algoritmiese metodiek vir komponent en stelsel betroubaarheid analise kan help om die weg te baan na die implementering van ten volle rekenaarmatige stogastiese analise van strukture. Di e studie se fokus is op die ontwikkeling van algoritmes vir komponent en stelsel betroubaarheid analise soos gegrond op verskeie voorgestelde metodes. Vakwerk strukture is gekies vir die doeleinde as gevolg van hulle eenvoud asook hulle wydverspreide gebruik in industrie. Die algoritmes wat in die studie ontwikkel is kan nietemin ook vir ander tipes strukture soos moment-vaste raamwerke gebruik word, gegewe eenvoudige aanpassings. Vir 'n komponent vlak betroubaarheid analise van strukture word verskeie metodes soos die "First Order Reliability Methods" (FORM) en simulasie metodes voorgestel. Die implementering van die metodes vir staties onbepaalbare strukture is ingewikkeld as gevolg van die implisiete verband tussen die gedrag van die struktuur stelsel en die las effek. As 'n gevolg, moet die algoritme wat ontwikkel word vir die doel van komponent betroubaarheid analise gebaseer word op die konsepte van stogastiese eindige element metodes ("SFEM") waar 'n duidelike verband tussen die eindige element analise van die struktuur en die betroubaarheid analise verseker is. In hierdie studie word verskeie algoritmes ontwikkel wat gebaseer is op die FORM metode, Monte Carlo simulasie, en die sogenaamde "Response Surface Method" (RSM). Vir die gebruik van die FORM metode word twee verdere metodologieë ondersoek: een gebaseer op die ontwikkeling van 'n eindige element kode waar nodige verandering aan die eindige element kode self gemaak word en die ander waar 'n kommersiële eindige element pakket gebruik word. Verskillende simulasie metodes word ook geïmplimenteer naamlik Direkte Monte Carlo Simulasie (DMCS), "Latin Hypercube Sampling Monte Carlo" (LHCSMC) en sogenaamde "Updated Latin Hypercube Sampling Monte Carlo" (ULHCSMC). Verder, word RSM tesame met die simulasie metodes gebruik. In die tesis word die doeltreffendheid van die bostaande metodes deurgaans ondersoek. 'n Ten volle stogastiese eindige element metode ("FSFEM") met verandering aan die eindige element kode blyk die vinnigste benadering te wees omdat die koppeling tussen die eindige element metode pakket en die betroubaarheid analise verhoed word. Simulasie metodes kan ook effektief aangewend word vir die betroubaarheid evaluasie waar ULHCSMC as die mees doeltre end voorgekom het, gevolg deur LHCSMC en DMCS. The RSM metode is die mees komplekse metode vir algoritmiese komponent betroubaarheid analise. Die metode is egter nuttig vir sisteem betroubaarheid analise. Vir sisteem-vlak betroubaarheid analise is twee metodes oorweeg naamlik die "ß-unzipping" metode and die "branch-and-bound" metode. Die "ß-unzipping" metode is gebaseer op 'n sisteem-vlak betroubaarheid ontleding waar die struktuur op verskillende skade vlakke gemodelleer word soos toepaslik vir die hoeveelheid addisionele las paaie. In elke vlak word die sogenaamde "unzipping" intervalle gedefinieer vir die identifikasie van die kritiese elemente. Die "branch-and-bound" metode is gebaseer op die identifikasie van verskillende faling roetes van die struktuur deur uitbreiding van die falingsboom. The ondersoek van die skade toestande vir beide metodes is dieselfde. Verder kan beide metodes lei tot die ontwikkeling van 'n parallelserie model van die strukturele stelsel. Die enigste verskil tussen die twee metodes is in die soek-benadering vir die uitkenning van falingsmodus volgorde. Dit word getoon dat die "ß-unzipping" metode 'n beter algoritmiese benadering is vir die ontleding van sisteem betroubaarheid vergeleke met die "branch-and-bound" metode. Die "branch-and- bound" metode word nietemin as 'n meer robuuste metode vir die uitkenning van die falings volgorde beskou. Een moontlike manier om die doeltre endheid van die "ß-unzipping" metode te verhoog is om groter "unzipping" intervalle te gebruik, wat moontlik is vir rekenaarmatige analise. Vir so 'n analise word vier hoof modules benodig naamlik 'n algemene heel-struktuur module, 'n beskadigde-struktuur module, 'n betroubaarheid analise module en 'n sisteem betroubaarheid analise module. In die tesis word verskillende rekenaar programme ontwikkel vir beide sisteem en komponent betroubaarheid analise. Die rekenaar programme word in die aanhangsels van die tesis aangebied.
232

A preliminary assessment of the hydrodynamics of the Touw River and Wilderness Lakes system with emphasis on the management of the estuary mouth

Donald, Ian R. 12 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The Touw River estuary and Wilderness coastal lakes is a sensitive system from a flooding and ecological viewpoint and, therefore, careful consideration is placed on the hydrodynamics and salinity levels within the system. The estuary consists of a “temporary open/closed” estuary, where during closed mouth conditions, the sand bar at the estuary mouth is artificially managed in an attempt to reduce flood water levels in the system. The reason behind this management strategy is the construction of residential property along the flood plains of the estuary and coastal lakes, which in the past, had been exposed to regular cycles of inundation during flood events. In an attempt to reduce flood water levels in all water bodies and hence reduce the risk of inundation, a management policy was formulated. The past and present management plan is to maintain the sand bar at Touw estuary mouth, during closed mouth conditions, at an elevation of between +2.1m to +2.4m MSL, based on proposals made by the CSIR in 1981. Recent flood events, after the implementation of the management policy, still occasionally result in significant inundation of residential property, which has raised concern for some interested parties over the effectiveness of the management strategy. Furthermore, a growing concern was also evident over the long term wellbeing of the system from an ecological viewpoint. Historical data shows significant changes in salinity levels since the implementation of the management strategy which could impose negative long term effects on the system. In this study, numerical models were consequently constructed and applied in order to analyse the effectiveness of the current management policy and recalculate flood water levels under a number of proposed scenarios. Long term salinity changes were also analysed in an attempt to better understand salinity propagation throughout the system, using extreme hypothetical cases. Through the analysis of the simulation results, it was concluded that flood water levels in the Touw estuary were almost completely dependent on the size of the Touw River flood and the initial height of the sand bar at the estuary mouth. Whereas, water levels in the coastal lakes are almost entirely dependent on the quantity of runoff into the lakes and their initial water levels. The current management plan, involving only artificial manipulation of the sand bar at the estuary mouth, therefore has a fairly insignificant effect on flood water levels achieved in the coastal lakes. Furthermore, it was concluded that the construction of the preparatory channel is a vitally important aspect of the current management plan and that skimming of the sand bar alone is ineffective to completely mitigate the risk of residential inundation along the banks of the Touw River. The salinity modelling study provided a first indication of the salinity characteristics within the system. It was found that the penetration of seawater into the system was less prominent as the water bodies became further removed from the ocean and that a direct relationship was evident between the volume of direct freshwater inflow to a water body and the degree of salinity variation in that specific water body. In water bodies with high volumes of direct freshwater inflow such as the Touw estuary, a large degree of salinity variation is evident. However, in water bodies with no freshwater inflow, such as Rondevlei, salinity levels remain more stable and are less likely to fluctuate. / AFRIKAANSE OPSOMMING: Uit ‘n vloed- en ekologiese oogpunt is die Touwsriviermonding en Wilderniskusmere ‘n uiters sensitiewe stelsel en daar is dus deeglike oorweging gegee aan die hidrodinamika en soutvlakke in die stelsel. Die monding bestaan uit 'n "tydelike oop / geslote" monding, en tydens geslote mondtoestande word die sandbank by die riviermond kunsmatig beheer in 'n poging om vloedwatervlakke binne die stelsel te verminder. Die rede vir hierdie strategie is omdat baie residensiële eiendomme langs die vloedvlaktes van die monding en kusmere gebou is, wat in die verlede aan 'n gereelde siklus van oorstromings blootgestel is tydens vloede. In 'n poging om vloedwatervlakke in al die watermassas te verminder, en sodoende die risiko van oorstroming te verminder, is 'n bestuursbeleid geformuleer. In beide die vorige en die huidige bestuursplanne is die sandbank in die Touwsriviermond tydens geslote mondtoestande in stand gehou op 'n hoogte van tussen 2,1 m en 2,4 m MSL, gebaseer op die voorstelle wat deur die WNNR in 1981 gemaak is. Onlangse vloede wat plaasgevind het na die implementering van die beleid, het steeds van tyd tot tyd gelei tot noemenswaardige oorstromings van residensiële eiendomme, en kommer is uitgespreek deur 'n paar belanghebbende partye oor die doeltreffendheid van die strategie vir die bestuur. Daar is verder kommer uitgespreek oor die langtermyn welstand van die stelsel uit 'n ekologiese oogpunt. Historiese data toon 'n beduidende verandering in soutvlakke sedert die implementering van die bestuurstrategie met ‘n negatiewe langtermyn uitwerking op die stelsel. In hierdie studie is daar derhalwe numeriese modelle opgestel en toegepas ten einde die doeltreffendheid van die huidige bestuur van die beleid te bepaal, asook om die vloedvlakke te herbereken en te analiseer na aanleiding van 'n aantal voorgestelde scenario's. Langtermyn soutgehalte veranderinge is ook ontleed in 'n poging om die soutgehalte verspreiding deur die hele stelsel beter te verstaan, deur gebruik te maak van uiterste hipotetiese gevalle. Deur die ontleding van die simulasie resultate, is daar tot die gevolgtrekking gekom dat vloedwatervlakke in die Touwsrivier-monding byna heeltemal afhanklik was van die grootte van die Touwsrivier vloed en die aanvanklike hoogte van die sandbank by die riviermond. Watervlakke in die kusmere is egter byna heeltemal afhanklik van die hoeveelheid afloop na die mere en die aanvanklike watervlakke. Die huidige bestuursplan, wat slegs ‘n kunsmatige manipulasie van die sandbank by die riviermond behels, het dus 'n redelik onbeduidend invloed op die vloedwatervlakke wat in die kusmere bereik is. Daar is verder tot die gevolgtrekking gekom dat die konstruksie van die voorbereidende kanaal 'n uiters belangrike aspek van die huidige bestuursplan is, en dat die afskraping van die sandbank alleen oneffektief sou wees om die risiko van residensiële oorstroming langs die oewer van die Touwsrivier uit te skakel. Die soutgehalte modelleringstudie verskaf 'n eerste aanduiding van die soutgehalte eienskappe binne die stelsel. Daar is gevind dat die penetrasie van seewater in die stelsel minder prominent was as in die watermassas verder van die see af, en dat daar 'n duidelike direkte verband is tussen die volume van die varswater wat direk invloei na 'n watermassa en die mate van soutgehalte variasie in daardie spesifieke watermassa. In watermassas waar hoë volumes varswater direk invloei soos die Touwsrivier-monding, is 'n groot mate van soutgehalte variasie sigbaar. In die watermassas waar geen varswater invloei nie, soos die Rondevlei, bly soutvlakke meer stabiel en is minder geneig om te wissel.
233

The structural use of synthetic fibres : thickness design of concrete slabs on grade

Bothma, Jacques 12 1900 (has links)
Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: Concrete is used in most of the modern day infrastructure. It is a building material for which there exist various design codes and guidelines for its use and construction. It is strong in compression, but lacks tensile strength in its fresh and hardened states and, when unreinforced, fails in a brittle manner. The structural use of synthetic fibres in concrete is investigated in this study to determine its effect on enhancing the mechanical properties of concrete. Slabs on grade are used as the application for which the concrete is tested. The material behaviour is investigated in parallel with two floor design theories. These are the Westegaard theory and the Yield-Line theory. The Westegaard theory uses elastic theory to calculate floor thicknesses while the Yield-Line theory includes plastic behaviour. Conceptual designs are performed with the two theories and material parameters are determined from flexural tests conducted on synthetic fibre reinforced concrete (SynFRC) specimens. Large scale slab tests are performed to verify design values from the two theories. Higher loads till first-crack were measured during tests with concrete slabs reinforced with polypropylene fibres than for unreinforced concrete. It is found that the use of synthetic fibres in concrete increases the post-crack ductility of the material. The Westegaard theory is conservative in its design approach by over-estimating design thicknesses. This was concluded as unreinforced slabs reached higher failure loads than predicted by this theory. The Yield-Line theory predicts design thicknesses more accurately while still accounting for the requirements set by the ultimate- and serviceability limit states. By using SynFRC in combination with the Yield-Line theory as design method, thinner floor slabs can be obtained than with the Westegaard theory. / AFRIKAANSE OPSOMMING: Beton word gebruik as boumateriaal in meeste hedendaagse infrastruktuur. Daar bestaan verskeie ontwerp kodes en riglyne vir die gebruik en oprig van beton strukture. Alhoewel beton sterk in kompressie is, het beton ‘n swak treksterkte in beide die vars- en harde fases en faal dit in ‘n bros manier indien onbewapen. Die gebruik van sintetiese vesels in beton word in hierdie projek ondersoek om die invloed daarvan op die eienskappe van die meganiesegedrag van beton te bepaal. Grond geondersteunde vloere word as toepassing gebruik. Parallel met die materiaalgedrag wat ondersoek word, word twee ontwerpsteorieë ook ondersoek. Dit is die teorie van Westegaard en die Swig-Lyn teorie. Die teorie van Westegaard gebruik elastiese teorie in ontwerpsberekeninge terwyl die Swig-Lyn teorie ‘n plastiese analise gebruik. ‘n Konseptuele vloerontwerp is gedoen deur beide die ontwerpsmetodes te gebruik. Materiaalparameters is bepaal deur buig-toetse uit te voer op sintetiesevesel-bewapende beton. Grootskaalse betonblaaie is gegiet en getoets om die akkuraatheid van die twee metodes te verifieer. Die betonblaaie wat bewapen was met polipropileen vesels het groter laste gedra tot by faling as die blaaie wat nie bewapen was nie. Die vesels verbeter die gedrag van beton in die plastiese gebied van materiaalgedrag deurdat laste ondersteun word nadat die beton alreeds gekraak het. Die Westegaard teorie kan as konserwatief beskou word deurdat dit vloerdiktes oorskat. Hierdie stelling is gegrond op eksperimentele data wat bewys dat onbewapende betonblaaie groter laste kan dra as wat voorspel word deur die Westegaard teorie. Die Swig-Lyn teorie voorspel ontwerpsdiktes meer akkuraat terwyl daar steeds aan die vereistes van swigting en diensbaarheid voldoen word. Deur gebruik te maak van sintetiese vesels en die Swig-Lyn teorie kan dunner betonblaaie ontwerp word as met die Westegaard teorie.
234

A dry port as an expansion option for the Cape Town container terminal

De Wet, Christiaan Johannes 04 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Currently maritime ports, including the Port of Cape Town, experience congestion, pollution and other logistics-related problems due to increasing levels of container traffic. The presence of these problems has caused port planners, port operators and logistics firms to look for new solutions in this transport sector. The dry port concept, whereby offloaded containers are stored outside the maritime port in a dedicated logistics area, is recognized as a means for solving some of these major problems, thereby promoting economic development and logistics integration as well as reducing the demand on limited capacity (land and access) at the maritime port. Therefore, the core objective of this study is to demonstrate that the implementation of the dry port concept is a feasible alternative for expanding the throughput capacity of the Cape Town Container Terminal. The Port of Cape Town is strategically one of the best placed ports in South Africa as it is positioned at the South Western extremity of the continent of Africa, thereby linking America and Europe with Asia, the Far East and Australia. Furthermore, the Port of Cape Town also forms a direct link between international trade and about three (3) million consumers in the Western Cape. The recent expansion of the Cape Town Container Terminal was a major investment which included the upgrading of equipment and the expansion of workable surface area, thereby increasing the container terminal yard capacity to 1.4million TEU (TEU = Twenty foot Equivalent Unit) per annum. However, this report showed that the abovementioned increase in volumes as well as the resulting congestion continues to be a challenge at the Port of Cape Town. Firstly, the predicted future container volumes show that the demand in the Port of Cape Town could reach between 1.9 million and 3.2 million TEU per annum by 2039. Secondly, the evaluation of the operational and infrastructural characteristics of the existing Cape Town Container Terminal demonstrated that container terminal yard (CY) area is the capacity limiting characteristic of the terminal and that the operational and infrastructural limits could be reached between 2018 and 2026. The two main functions of a dry port in the Western Cape transportation network would be international trade processing and congestion relief, which are achieved through the duplication and supplementation of the Cape Town Container Terminal facilities at an inland location. The dry port would allow the Western Cape supply chain to absorb any future container volume demands that exceed the CY capacity of the Port of Cape Town and could potentially attract an annual throughput of 0.7 million TEU by 2039. Furthermore, the facility could address the problem of congestion in and around the greater Cape Town metropolitan, resulting in an improved transportation network that will have a positive effect on passenger traffic, productivity of trucks, competitiveness of the Port of Cape Town as well as the environmental sustainability of the transportation system. The dry port concept would therefore be appealing to Transnet Port Authority / Transnet Port Terminals, Shippers and Logistics Managers and the Western Cape Regional Community. The site selection analysis performed in this study evaluated three possible dry port locations, namely: Kraaifontein Area, Ysterplaat Air Force Base and Bellville Precinct. Although the analysis identified that all three of the sites have the potential to be developed into a successful dry port; however, that the Bellville Precinct is the preferred location due to the presence of the Belcon freight rail facility. The success of such a facility will greatly depend on the project’s ability to ensure that the resources needed for the initial investment is kept to a minimum, and ultimately the most viable dry port solution in the Western Cape region would be the phased development of Bellville Precinct. From this it is clear that a dry port could be a feasible alternative for expanding the throughput capacity of the Port of Cape Town, as well as improving the transport infrastructure in the Cape Town area. / AFRIKAANSE OPSOMMING: Maritieme hawens, insluitende die Kaapstadse hawe, ondervinding tans opeenhoping, besoedeling en ander logistieke probleme as gevolg van toenemende vlakke van die houer verkeer. Die teenwoordigheid van hierdie probleme het veroorsaak dat hawe beplanners, hawe-operateurs en logistiek maatskappye op soek is vir nuwe oplossings in die vervoer sektor. Die droë hawe konsep word erken as 'n middel vir die oplossing van sommige van hierdie probleme, en sodoende ekonomiese ontwikkeling en logistieke integrasie te bevorder, sowel as die verlaging van aanvraag op beperkte kapasiteit (grond en toegang) by die maritieme hawe. Daarom is die kern doel van hierdie studie om aan te toon dat die implementering van die droë hawe konsep 'n haalbare alternatief is vir die uitbreiding van die deurset kapasiteit van die Kaapstadse Houerterminaal. Die Kaapstadse hawe is strategies een van die bes geplaaste hawens in Suid-Afrika, want dit is geleë aan die suid-westerlikste punt van Afrika en verbind Amerika en Europa met Asië, die Verre Ooste en Australië. Verder vorm die Kaapstadse hawe ook 'n direkte skakel tussen die buitelandse markte en die drie (3) miljoen verbruikers in die Wes-Kaap. Die onlangse uitbreiding van die Kaapstadse Houerterminaal het die stoorkapasiteit van die terminaal aansienlik verbeter an 1.4 miljoen TEU per jaar, deur middel van die opgradering van toerusting en die uitbreiding van werkbare oppervlak. Hierdie verslag bewys egter dat die bogenoemde toename in volumes sowel as die gevolglike opeenhoping steeds teenwoordig is in die Kaapstadse hawe. Eerstens, die voorspelde toekomstige houervolumes toon dat die aanvraag in die Kaapstadse hawe tussen 1.9 miljoen en 3.2 miljoen TEU's per jaar kan bereik teen 2039. Tweedens, die evaluering van die operasionele en infrastrukturele kenmerke van die bestaande Kaapstadse Houerterminaal het getoon dat die houer stoorarea die kapasiteit beperkende kenmerk van die terminaal is en dat die operasionele en infrastrukturele perke moontlik tussen 2018 en 2026 bereik kan word. Die twee hoof funksies van 'n droë hawe in die Wes-Kaap vervoer netwerk sal internasionale handel verwerking en opeenhoping verligting wees. Hierdie funksies sal bereik word deur die duplisering en aanvulling van die Kaapstadse Houerterminaal fasiliteite by 'n binnelandse perseel. Die droë hawe sal toelaat dat die Wes-Kaap verskaffersiklus enige toekomstige houervolumes, wat meer is as die houer stoorarea kapasiteit van die Kaapstadse hawe, te kan hanteer en kan potensieel 'n jaarlikse deurset van 0.7 miljoen TEU hanteer. Verder kan die
235

Effect of paper mill ash on properties of expansive soils

Byiringiro, Alfred 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Expansive soils, one of the problematic soils, are encountered on all continents with exception of polar continents. Problems caused by their heaving and shrinking behaviour, particularly to light structures, have been reported from different countries to place large financial burden on developers. For this reason, many techniques have been developed and applied to prevent and/or remediate the damage caused by these soils. Soil stabilization with traditional chemical additives has been applied successfully since ancient times. In addition to traditional additives such as lime, cement, fly ash, etc., some non-traditional additives, such as polymer based products, salts, etc. have been used effectively for soil treatment. On the other hand, industries are increasingly challenged by waste management in an acceptable and environmentally friendly manner. In this regard, a number of researches have been done on using industrial waste for soil improvement purposes. The study and understanding of basic reactions involved in lime-soil stabilization persuaded many researchers to study the applicability of lime-rich products for soil treatment. Studies conducted by Khalid et al. (2012); Muchizuki et al. (2004) and Thacker (2012) showed that lime-rich products such as pulp fly and bottom ashes and CaO by-products, can be applied for soil stabilization. This research was thus performed to investigate the effect of lime-rich paper mill waste ash on expansive soil properties. Two commonly listed soil engineering properties namely volume change and strength were investigated. Soil strength was examined in terms of unconfined compressive strength (UCS), due to its correlations with a number of other soil properties, and the volume change in terms of free swell and swelling pressure. In addition to these two engineering properties, dry density and moisture content were also studied due to their involvement in structural design, as well as gradation, Atterberg limits and California Bearing Ratio (CBR). The choice of these properties was also influenced by the availability of a standard (ASTM D4609-08) specifically developed to assess the effectiveness of admixtures for soil stabilization. Two main types of materials were used namely three clay materials and paper mill ash. According to the index properties, commonly used for expansive soil classification, three clays were classified into low, medium and high degrees of potential expansiveness. The ash results from the combustion of paper mill sludge, sawdust, bark, coal ash and bituminous coal in a multi-fuel boiler for the purpose of electricity and steam production. The tests mentioned above were conducted on both untreated and treated clays and the results were compared. Since the study was carried out on this material based on the fact that it contains lime, the procedure applied for lime-soil stabilization was considered. In general, it was observed that ash-soil treatment has a number of effects similar to lime-treatment and almost all studied properties were enhanced for all clays. It can thus be concluded that the paper mill ash from a multi-fuel boiler can be efficiently used for expansive soil treatment. For optimum use of this material for expansive soil treatment, more tests and further researches have been recommended. / AFRIKAANSE OPSOMMING: Uitsettende gronde, een van die probleemtipe-gronde, kom op alle kontinente voor, behalwe die twee poolkontinente. Probleme veroorsaak deur uitswellende en inkrimpende gedrag van hierdie gronde, veral finansiële onkostes van ligte strukture is al in baie lande aangemeld. Vir hierdie rede is baie tegnieke ontwikkel en toegepas om skade wat deur hierdie tipe gronde veroorsaak is, te voorkom en/of herstel. Hierdie tegnieke sluit grondstabilisasie met chemiese bymengsels in, veral tradisionele bymengsels, wat met groot sukses in die verre verlede toegepas en na moderne tye oorgedra is. Bykomend tot tradisionele bymengsels soos kalk, sement, vlieg-as ensovoorts is ʼn aantal nie-tradisionele bymiddels soos polimeergebaseerde produkte, soute en ander produkte ontwikkel vir grondstabilisasie. Aan die ander kant raak industrieë toenemend daarmee gemoeid om afvalstowwe op ʼn aanvaarbare en omgewingsvriendelike wyse te bestuur. Op hierdie gebied is ʼn aantal navorsingsprojekte al uitgevoer om industriële afval vir grondverbetering te gebruik en sodoende die las op nywerhede te verlig. Navorsing is onderneem om die basiese reaksies wat onstaan tydens stabilisasie van grond met tradisionele en moderne middels te bepaal en om die geskiktheid van kalkryke produkte vir grondstabilisasie te ondersoek. Baie navorsing is uitgevoer wat aangetoon het dat kalkhoudende produkte soos pulp vlieg- en oondresidu-as, asook CaO neweprodukte gebruik kan word vir stabilisasie. Gebaseer hierop is hierdie projek onderneem om die effek van papiermeulas, verkry deur die verbranding in ʼn veelvuldige brandstof-stoomketel, op die gedrag van uitsettende grond te ondersoek. Tydens hierdie studie is twee algemene ingenieurseienskappe van grond, naamlik sterkte en volumeverandering ondersoek. Grondsterkte is geëvalueer in terme van eenassige druksterkte (EDS) as gevolg van ? deur middel van die korrelasie met ʼn aantal ander grondeienskappe, en die volumeverandering in terme van vry-swel en sweldruk. Addisioneel tot hierdie twee grondeienskappe is droë digtheid en waterinhoud ook bestudeer aangesien beide in struktuurontwerp betrokke is. Verdere eienskappe wat ondersoek is, is gradering, Atterberggrense en Kaliforniese drakragverhouding (KDV). Die keuse van hierdie eienskappe is beïnvloed deur die beskikbaarheid van ʼn toetsstandaard (ASTM D4609-08) wat spesifiek ontwikkel is om die effektiwiteit van bymengsels vir grondstabilisasie te evalueer. Hierdie standaard is deurgaans as verwysing tydens die projek gebruik. Daar is waargeneem dat as-behandeling van grond ʼn aantal effekte het soortgelyk aan kalkbehandeling, met die uitsondering van die droë digtheid en optimum waterinhoud van een van die gronde wat getoets is. Byna al die eienskappe wat ondersoek is, soos EDS, KDV, ensovoorts, is verbeter behalwe in die geval van die eerste klei waarvan die plastisiteitsindeks verhoog het en die grond meer plasties geraak het. Daar kan dus afgelei word dat papiermeule-as vanaf ʼn stoomketel wat veelvuldige tipes brandstof gebruik geskik is vir die behandeling van uitsettende grond. Om die optimumgebruik van hierdie materiaal vir die stabilisasie van swellende klei te bepaal, is meer toetse en projekte nodig.
236

An investigation of the document bias between the GCC 2004 and the GCC 2010

Klingenberg, Wolfram Georg 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / Construction projects have developed over several decades through the advancement of technology, increased scarcity of resources and the ever increasing pressure of time and cost constraints. Because of new technology and modern construction methods, construction projects have become increasingly complex. These complexities inherently bring new risks that must be dealt with accordingly. A contract is the primary method through which risks are allocated between the Employer and the Contractor. The conditions allocating the risks legally bind both parties to accept responsibility of those risks, therefore it is important to understand the aspects of law that has bearing on contracts. In this thesis the scope is restricted to construction contracts. Because of the role that a contract plays, especially in the construction industry context, it is important to know the requirements of a modern contract to ensure the successful completion of projects and the continued sustainability of Employer-Contractor relationships. In South Africa, the Construction Industry Development Board (CIDB) is a body that monitors developments in the construction industry. The CIDB has the authority to enforce legislation to ensure that contracts conform to a standard that protects the interests of both the Employer and the Contractor. One of the procurement documents endorsed by the CIDB is the General Conditions of Contract for Construction Works published by the South African Institution of Civil Engineering (SAICE). The first edition of the GCC was published in 2004 (GCC 2004) and a revised second edition was published in 2010 (GCC 2010). In this study the GCC 2010 and the GCC 2004 are compared first through a content analysis, to establish the effect the revisions on the bias of the document (or favouring a particular party) and then by means of a survey. The objectives are: a. To test whether revisions to the GCC from the 2004 edition to the 2010 edition resulted in a change in bias (assuming it exists) and compliance with the requirements of the modern contract; b. To determine the extent and effect of alterations to standard clauses of the GCC 2010 on the way in which the contract favours a particular party; c. Providing recommendations for future revisions that would potentially improve project success, relationship building and reduce the need for significant alterations to the standard clauses. Although a construction contract is undertaken between the Employer and the Contractor, the Consultant (who is not party to the contract) commonly drafts the contract on behalf of the Employer. The findings of the study show that the revision had a significant impact on improving the clarity of the roles of the Employer and the Contractor. A marginal improvement was found in the area of payment operating mechanisms. The perceived fairness of the document neither increased nor decreased. Clauses on claims and disputes and risk and related matters were the two areas that respondents identified as having the most bias that may be detrimental to the success of a construction project. Despite survey respondents finding the GCC 2010 procurement document to be fair, clauses are still altered by Employers (probably through Consultants) resulting in a biased contract favouring the Employer. Employers and Consultants should thus be educated more on bias and fairness in contracts and on the implications of shifting more risk to Contractors by altering clauses. Ultimately, the success of any construction project is dependent on the attitudes of the participants. Even the most fair procurement document is not a substitute for a relationship built on honesty and trust.
237

Personnel Allocation for Engineering Projects

Theron, Louis Francois 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The logical allocation of tasks in engineering offices currently relies heavily on the experience and intuition of project managers. In large scale projects the complexity of the task allocation procedure exceeds the capacity of human intuition, and a systematic technique is required to aid project managers in assigning tasks to individuals. In this project such a systematic technique is modelled and implemented using the Java programming language. An equation was developed to calculate an individual’s workload, and used in conjunction with other criteria to intelligently and systematically select an optimal individual to complete engineering tasks. The software solution is network-based, and also aims to aid project managers in various managerial duties. / AFRIKAANSE OPSOMMING: Die logiese toekenning van ingenieurstake steun tans swaar op die ervaring en aanvoeling van projek bestuurders. In grootskaalse projekte is die kompleksiteit van die taak toekenningsproses veel groter as die kapasiteit van menslike intuïsie. Dus word ‘n sistematiese proses wat projek-bestuurders kan help met die toeken van take aan individue vereis. In hierdie projek is so 'n sistematiese tegniek ontwikkel en geïmplementeer met behulp van die Java-programmeringstaal. 'n Vergelyking is ontwikkel om 'n individu se werklading te bereken en is in samewerking met ander kriteria gebruik om take intelligent en sistematies toe te ken. Die sagteware is network en databasis-gebaseerd en kan ook gebruik word om projek-bestuurders te help met verskeie bestuurspligte.
238

Validation of computational fluid dynamics model of a simple pump sump with vertical intake

Hoppe, Mark Mathew 04 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The designs of pump intake structures are generally verified by means of a hydraulic model study to ensure the structure will operate without large air or swirl entraining vortices. This is an expensive and time consuming process. The popularity of Computational Fluid Dynamics (CFD) is ever increasing in the engineering world and the use thereof in the modelling of flows in pump intake structures is just one of the many areas of focus. The use of a validated CFD model in the design phase of pump intakes would be beneficial, and ideally would reduce the frequency of requiring hydraulic model studies. This study investigates the applicability of using a 3 dimensional CFD model as a design tool by validation with a physical model. A physical model of a simple pump intake was available and with a few modifications the flow conditions were significantly improved. The quantitative validation of the CFD model was carried out by means of comparing corresponding point velocity magnitudes. An Acoustic Doppler Velocimeter (ADV) was used in the physical model. The data obtained were successfully filtered to remove noise and other disturbances. The qualitative validation was done by means of photographs and observations. The photographs made use of illuminated tracer particles to identify flow patterns. The CFD model compares well qualitatively, but the velocity magnitudes are not yet sufficiently reliable. It is recommended that the CFD model can be used for qualitative studies, but future research should focus on the accuracy of the CFD model. Using higher resolution velocity measurements in the physical model by means of other types of instruments, a better comparison can be made, as well as enabling validation of the ADV readings. / AFRIKAANSE OPSOMMING: Die ontwerpe van die pomp inname strukture word gewoonlik bevestig deur middel van 'n hidrouliese model studie om lug-intrekking te minimeer. Dit is 'n duur en tydrowende proses . Die gebruik van Computational Fluid Dynamics ( CFD ), ‘n tipe numeriese modelle neem toe in die ingenieurswese wêreld. Die gebruik daarvan in die modellering van vloei in pomp inname strukture is net een van die vele areas van toepassing . Die gebruik van 'n betroubare CFD model in die ontwerp fase van pomp innames sal voordelig wees , en ideaal sou die noodaaklikheid van fisiese hidrouliese model studies verminder. Hierdie studie ondersoek die toepaslikheid van die gebruik van 'n 3 -dimensionele model CFD model as 'n ontwerp instrument deur bevestiging met 'n fisiese model . 'n Eenvoudige pomp-inname model was beskikbaar en het met ‘n paar veranderinge die vloei toestande aansienlik verbeter . Die kwantitatiewe bevestiging van die CFD model is uitgevoer deur middel van vergelyking van korresponderende punt snelheid groottes. In die fisiese model is die snelhede met 'n Akoestiese Doppler Velocimeter (ADV) gemeet. Die data wat verkry is suksesvol gefiltreer om geraas en ander versteurings te verwyder . Die kwalitatiewe bevestiging is gedoen deur middel van foto's en waarnemings. In die foto's is gebruik gemaak van verligte spoor deeltjies om vloei patrone te identifiseer. Die CFD model vergelyk kwalitatief goed, maar die snelheid groottes is nog nie voldoende betroubaar nie. Dit word aanbeveel dat die CFD model gebruik kan word vir kwalitatiewe studies, maar toekomstige navorsing behoort te fokus op die verbeteringe van dieakkuraatheid van die CFD model. Met behulp van 'n hoër resolusie snelheid metings van die fisiese model, deur middel van ander tipe instrumente, kan 'n beter vergelyking gemaak word , sowel as die geldigheid van die ADV lesings in staat te stel.
239

Impermeable recurve seawalls to reduce wave overtopping

Schoonees, Talia 04 1900 (has links)
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.
240

A two-dimensional numerical model for the investigation of the effects of dams on the Zambezi River Delta

Kime, Robyn Laura 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The Zambezi River is the largest east-draining river in Africa. It captures runoff from 8 different countries before draining into the Indian Ocean in Mozambique through the Zambezi Delta which is recognised as a (Ramsar) Wetland of international importance. The Zambezi River flows are currently regulated by four large hydropower dams within its catchment. Much attention has been given in recent literature to the detrimental effects of the altered flow regime as a result of dams on the Zambezi River and the Delta in particular. Existing research relating to these negative effects includes many detailed ecological, hydrological and qualitative morphological studies but to date no detailed morphological modelling studies have been conducted in this regard. In this thesis a two-dimensional coupled hydrodynamic and morphological numerical model of the Zambezi Delta is created using topographical information obtained from a navigational study (Rio Tinto, 2011). The model hydrodynamics are calibrated using recorded water levels and flows at two gauging stations within the model domain. The bed load sediment transport is calibrated using field measurements (ASP, 2012b). The effects of dams on the Zambezi Delta are investigated by performing two 10 year simulations, one representing the current (post-dam) scenario and the other representing a pre-dam scenario. These simulation results show a significant decrease in flooded areas and sediment movement on the floodplains as a result of dams. Additional effects on channel widths and depth, on bed gradings, and on tidal water level variations are analysed. The model is then used to simulate a proposed environmental flood release scenario. Such releases have been recommended as a means to partially mitigate the negative impacts of dams on the Zambezi River. In this case an annual flood release supplying a peak flow of 8500 m3/s (slightly less than the pre-dam mean annual flood of 10 000 m3/s) was found to cause slightly more flooding of the close floodplains and to have small effects on the river channel width. The model predicts hydrodynamics and bed sediment transport of non-cohesive sediments with suitable accuracy but an issue with the suspended transport of cohesive sediments was identified. Recommendations are made for addressing the suspended sediment transport inaccuracy. The model, in its current form, can provide quantitative information regarding the hydrodynamics and course sediment transport of the general delta region on a coarse scale. With additional computational resources and accurate topographical information the model can be refined to give accurate predictions for localised areas within the delta. Such information would be valuable to specialist studies addressing the environmental effects of various proposed flooding scenarios or future dams. / AFRIKAANSE OPSOMMING: Die Zambezirivier is die grootste oos-dreineerende rivier in Afrika. Dit ontvang afloop van ag verskillende lande voor dit in die Indiese Oseaan in Mozambiek uitmond. Die Zambezidelta work erken as 'n RAMSAR vleiland van internasionale belang. Die vloei in die rivier word tans gereguleer deur vier groot hidro-elektriese damme binne sy opvangsgebied. Baie aandag is in die onlangse literatuur gegee aan die nadelige gevolge van die veranderde vloei as gevolg van damme op die Zambezi Rivier en spesifiek op die Delta. Bestaande navorsing met betrekking tot hierdie negatiewe effekte sluit in detail ekologiese, hidrologiese en kwalitatiewe morfologiese studies, maar tot op datum is geen gedetailleerde morfologiese modelleringstudies gedoen nie. In hierdie tesis is 'n twee-dimensionele gekoppelde hidrodinamiese en morfologiese numeriese model van die Zambezi Delta geskep met behulp van topografiese inligting wat verkry is uit 'n navigasiestudie (Rio Tinto, 2011). Die model hidrodinamika is gekalibreer deur teen watervlakke en vloei by twee meetstasies in die model domein. Die bedvrag sedimentvervoer is gekalibreer met behulp van veldmetings (ASP, 2012b). Die ȉnvloed van die damme op die Zambezi Delta is ondersoek deur twee 10-jarige simulasies, een wat die huidige ( na-dam ) scenario en die ander wat 'n voor-dam scenario ondersoek. Hierdie simulasie resultate toon 'n beduidende afname in die oorstroomde gebiede en sedimentbeweging op die vloedvlaktes as gevolg van damme. Bykomende effekte op kanaalbreedtes en -diepte, op die bedgraderings , en op getywatervlak variasies is ontleed. Die model is vervolgens gebruik om 'n voorgestelde omgewingings vloedloslaating te ondersoek. Sodanige loslaatings is aanbeveel om die negatiewe impak van damme op die rivier gedeeltelik te verminder. In hierdie geval gee 'n jaarlikse vloedloslaating met 'n piekvloei van 8500 m3/s (effens minder as die voor-dam gemiddelde jaarlikse vloed van 10 000 m3/s) effens meer oorstromings van die vloedvlaktes en het 'n klein uitwerking op die rivierkanaalbreedte. Die model voorspel die hidrodinamika en bedsedimentvervoer van nie-kohesiewe sedimente met betroubaarheid, maar 'n probleem met die vervoer van kohesiewe sedimente is geïdentifiseer. Aanbevelings word gemaak vir die aanspreek van die kohesiewe sedimentvervoer onakkuraatheid. Die model, in sy huidige vorm, kan kwantitatiewe inligting oor die hidrodinamika en natuurlik sedimentvervoer van die algemene delta streek by benadering verskaf. Met bykomende rekenaar hulpbronne en akkurate topografiese inligting kan die model verfyn word om akkurate voorspellings vir plaaslike gebiede binne die delta te gee. Sulke inligting kan waardevol wees vir spesialis-studies van die omgewingsimpakte van verskillende voorgestelde vloedloslaatings of toekomstige damme.

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