Thesis (MEng (Civil Engineering))--University of Stellenbosch, 2007. / The failure rate of electric overhead travelling crane supporting structures across the world is unacceptably high. Failures occur even when the supporting structures are designed within the relevant design codes. This demonstrates a lack of understanding of the dynamic behaviour of cranes in many design codes. The current South African loading code is simplistic with respect to crane supporting structure design, relying on empirical factors to determine the correct loads. While these factors lead to predicted forces in the correct range of values, the Eurocode’s methods are more scientifically based. In recognition of this the draft South African code predominantly incorporates the methods used by the Eurocode to calculate design forces for crane supporting structures. The purpose of this thesis was to use an existing numerical model to determine the wheel loads induced by a crane into the crane supporting structure through hoisting, normal longitudinal travel, skewing and rail misalignment. The numerically obtained forces were then compared with the design forces estimated in the current South African code and the Eurocode, in order to determine whether the factors and methods used in the codes are accurate. The current empirically based South African code was found to be highly conservative. In contrast the scientifically based design forces from the Eurocode were close to the numerically calculated forces, only failing to predict the behaviour of the crane in the case of skewing. Further work needs to be completed in the estimation of forces induced during this load case. Once this is achieved it is hoped that the better understanding of the crane forces adapted from the Eurocode into the draft South African code will lead to a reduction in failures of electric overhead travelling crane supporting structures.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2009. / The need for a more reliable testing procedure for the characterisation and Quality Assurance/ Control of Bitumen Stabilised Materials (BSMs), besides UCS and ITS testing, has long been recognised by the roads industry. In fact, at CAPSA 2004 and CAPSA 2007, discussions of improved test methods for granular materials, i.e. possible replacement tests for CBR procedures, were conducted in workshops. Triaxial testing for the evaluation of shear parameters is widely recognised as a reliable method of measuring these critical performance properties of granular and Bitumen Stabilised Materials (BSMs). However, the triaxial test in its current state as a research test has little chance of extensive use by practitioners and commercial laboratories, because of complexity, cost and time issues. Major adaptations to the research triaxial test are necessary, before this useful test can have a chance of being accepted by road practitioners. The main aim of this study is to investigate possibilities of developing a simple, affordable, reliable and robust test for characterizing granular and bitumen stabilized materials thus linking test outcome with in-situ performance. This is achieved through the innovative design and manufacture of a prototype triaxial cell capable of accommodating 150 mm diameter by 300 mm deep specimens. The cell is simpler than the research (geotechnical) triaxial cell and the operational protocols have been streamlined, thereby reducing the time and steps required in assembling specimens and testing them. In order to ensure the development of an appropriate triaxial cell for industry, a survey was conducted aimed at investigating currently available facilities, testing capacity and resources within civil engineering laboratories in South Africa. Findings of the survey (Appendix 4) have provided guidance with regard to the nature and sophistication of any new tests to be developed. The survey highlighted some of the limitations and lack of sophistication of the current loading frames used for CBR and UCS testing such as lack of electronic LVDTs, limited overhead space, limited loading capacity and others. Most laboratories would need to invest in new loading facilities to carry out triaxial tests. A review of the test procedure for monotonic triaxial test showed that two main factors contribute to the complexity of the research (geotechnical) triaxial cell namely, time taken to assemble the specimen accurately in the cell and secondly the inherent design of the cell which makes it water and/or air tight at relatively high pressures. The design of the Simple Triaxial Test, therefore, was aimed at overcoming the drawbacks of research triaxial test e.g. fitting a membrane to each specimen to be tested, through considerable simplification by means of a new structure design and procedure of assembly of specimen into the cell. The advantage of addressing these issues would be reduction in the number of steps required in the test procedure and therefore reduction in testing time. The design of the cell particularly was preceded by a conceptualization process that involved investigation of numerous options. Concepts such as the bottle, encapsulated-tube, bottle and sandwich concepts were considered and given reality checks. In addition, available triaxial procedures of a similar nature e.g. Texas Triaxial, were evaluated and analyzed. Ultimately, with some trials and innovation, a design was developed for a simple triaxial cell comprising a steel casing with a latex tube which is then introduced around the specimen sitting on a base plate. It is based on the ‘tube concept’ in which the specimen acts like a ‘rim’ and the cell acts like a ‘tyre’ providing confinement to the triaxial specimens for testing, within the tube. This approach eliminates the use of O-rings and membranes for the specimen and tie-rods for the triaxial cell, thus reducing testing time considerably. The overall dimensions of the cell are 244 mm diameter by 372 mm height (Appendix 5). The cell was manufactured at Stellenbosch University Civil Engineering workshop and preliminary tests were conducted under this study. Parallel tests were also conducted with the Research Triaxial Test setup at Stellenbosch University in order to determine if preliminary results obtained with the Simple Triaxial Test setup were comparable therefore providing a means of validating the data. Results of analysis of variance (ANOVA) show that variability between Simple Triaxial Test (STT) and Research Triaxial Test (RTT) results is less significant whilst that within samples of STT and RTT results is quite significant. Comparisons also show that good correlation were obtained from Reclaimed Asphalt Pavement (RAP) Hornfels + 3.3 % Emulsion + 0 % Cement mix and mixes with the G2 base course aggregate whilst completely different correlation was obtained from RAP + 3.3 % Emulsion + 1% Cement. It is evident however that the differences observed stem from material variability i.e. random variability to one degree or the other and not to the STT apparatus. It is recommended for future research that more STT versus RTT testing be done especially on a mix with known mechanical properties when compacted to a specified dry density, e.g. graded crushed stone (G1) compacted to 100% mod. AASHTO. In summary, a locally made, low cost, relatively durable triaxial cell with relatively easy and quick specimen assembly procedures has been developed. It is now possible to perform triaxial tests on 150 mm diameter by 300 mm high specimen relatively easily and quickly. However, the challenge of validating results obtained, as well as improving the manufacture process of its main component, the tube, still remains.

Thesis (MScEng (Civil engineering))--University of Stellenbosch, 2005. / In this study, the minimum standards required for the design of rural piped water supply projects as set by the Department of Water Affairs and Forestry (DWAF) are evaluated with respect to capital pipe cost using the Nooightgedacht rural water supply scheme selected as a case study.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2007. / Bonded overlays are increasingly used in concrete and reinforced concrete repair and rehabilitation applications, despite the high probability of interfacial debonding. Reasons for such failures include inefficient substrate surface preparations, inappropriate overlay materials, poor curing conditions and time dependent influences. The introduction of engineered cement-based composite (ECC) as an overlay or repair material, does not only address durability aspects but also structural performance. The associated ductility of the material induces a high performance aspect where applied. It is crucial to execute reliable design methods, especially at interfacial level, in order to harness the ductility at hand. The fact of the matter is that through identifying the required performance, one can engineer an optimal bond through implementation of reliable substrate surface preparation techniques (SSPT’s). ECC is a material which exhibits ductile mechanical behaviour. The material matrix is reinforced with synthetic fibres, in the case of this study, poly vinyl alcohol (PVA) fibres were used. The introduction of fibres induces strain-hardening behaviour when in tension. Strain-hardening occurs from the first crack onwards and is accompanied by ductile behaviour, due to a multiple cracking phenomenon. Multiple cracking continues until the increased tensile load incurs localising of an existing crack. The literature study investigates bond properties and bond model parameter test methods. A review of composite design, mainly concrete to concrete, in local and international codes discloses design specifications towards calculating interfacial shear bonds. The interfacial transition zone (ITZ) between the aggregate and cement matrix of concrete is used to define the interfacial bond characteristics and processes. The next step is to investigate a variety of interfacial shear and tensile test methods, in order to implement the most suitable tests.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2006. / Modelling of the transport of fine cohesive sediments, as found in most South African reservoirs, has not been well developed. This is because the transport processes that are involved are complex and the theories not as implicit as the traditional equilibrium transport theories for coarse non-cohesive sediment. Advection and dispersion are found to be the processes that best describe the transport of fine sediments in turbulent flow conditions. A two-dimensional modelling tool, MIKE 21C, which simulates reservoir hydrodynamics and cohesive sediment transport processes with an advection-dispersion model, was evaluated in this thesis. The creation of such a numerical model involves the setting up of a suitable curvilinear grid and requires data on the bathymetry, recorded inflows as well as water levels. It also requires sediment characteristic parameters and transport parameters. These parameters have to be specified by the user based on previous studies and field measurement data. MIKE 21C was applied to laboratory flume tests and reservoir case studies in the field in order to determine the effects that these parameters have on the sediment transport in a series of sensitivity studies. Ranges were determined within which these parameter values should fall. A procedure was also developed through which reservoir sedimentation models can be calibrated.

Thesis (MEng (Civil Engineering))--University of Stellenbosch, 2007. / An extended project was undertaken to develop structural design software (called the integrated software) that supports network collaboration. Three projects preceded this thesis study in which the development of the integrated software was initiated. In these projects three software architectures were developed for a finite element model, a structural steel member design model and a structural steel connection design model. These projects cover the analysis and design aspects of the integrated software. This thesis study addresses the communication aspects of the integrated software. The communication aspects include communication between the various modules of the integrated software as well communication between people and between people and the software. No graphical user interface for the creation of finite element models was developed in the preceding projects, which was done in this thesis. The models developed in the preceding projects must be able to communicate with one another in order for the software to operate as a whole. Some of the communication links required in the integrated software are established in this thesis study. The communication of the integrated software is not to be confined to a local workstation. Therefore a software architecture is built into the integrated software in order to support network communication, thereby making network-based collaborative design a real possibility. The integrated software that is being developed is specifically for use by structural engineers. Therefore the engineers’ opinion of such design software that supports network collaboration is invaluable. In the last part of the thesis practicing engineers the views of are reported on topics of how collaborative designs could be done in practice and how it could be supported by design software. The results of the interviews are then summarized and an assessment is made of the engineers’ requirements for software that supports network collaboration. Finally recommendations are made for the future development of the integrated software.

Thesis (MScEng (Civil Engineering)--University of Stellenbosch, 2007. / The introduction of toughened glass into the construction industry has had several significant consequences. For the first time, glass panels can be used without continuous edge supports, and as a result can be used as load-bearing element. An excellent and very common example of the use of glass as structural element is a freestanding glass balustrade. During an undergraduate investigation, a number of impact tests were performed on continuous supported freestanding glass balustrade panels at the University of Stellenbosch [6]. It was observed that none of the balustrade panels complied with the guidelines for impact loading stipulated in the SABS [7] loading standards. The failure to meet the loading requirements highlighted the need to investigate the design of glass balustrades. This thesis describes the investigation undertaken to determine the static- and dynamic loading capacity of freestanding glass balustrades. Following a review of South African and international design standards, the static- and dynamic material properties of toughened glass was established by means of a laboratory test series. The laboratory test series consisted of both a destructive laboratory test series and finite element analysis, the outcome of which determined the static- and dynamic material properties of toughened glass. The series also included the influence of different connection types. A second phase employed the identified material properties of toughened glass to determine the loading capacity of full-scale balustrades. Using finite elements each balustrade set-up was loaded as required by the relevant South African loading standards. The finite element analyses identified which balustrade set-ups could resist the required imposed loads. Finally, a second laboratory test series was undertaken, the aim of which was to verify the finite element results. The successful resistance of the tested balustrade set-ups confirmed the finite element model. Recommendation to the existing design- and loading standards are made based on the results of the thesis.

Thesis (MEng (Civil Engineering))--University of Stellenbosch, 2001. / This Traffic Impact Assessment (TIA) was commissioned in March 1998 as a supporting document to an application for the rezoning of an ert in Noordhoek from general housing to commercial use. The proposal at the time was to develop a medium·sized 15 000 m2 GLA shopping centre with supporting offices and a Health & Racquet Club. All the work (including managing the traffic counting team) was carried out by myself under the guidance of Dr Piet Jordaan at Gibb Africa Consulting Engineers. As financial backing and anchor tenants were secured for the development, the size of the proposed shopping centre was increased from a local facilily to a regional facilily of 31 000 m2 GFA to be developed in two phases. This necessitated a complete revision of the approach and content of the TIA. Owing to the regional nature of the new development, the TIA was expanded to include a wider geographical area of influence and a longer development period. This revised TIA was carried out by myself between September 1998 and March 1999 under the guidance of Dr Herman Joubert. Longbeach Mall opened for business in April 2001 complete with upgraded road network as recommended in the TIA The TIA is submitted as the final-year project for my Master's Degree in Traffic & Transportation Engineering. For the purposes of completion, an after·study of current traffic conditions on the local road infrastructure has also been included. The after·study was carried out in October 2001 (6 months after Longbeach Mall opened) and includes traffic counts at critical intersections during the Saturday morning peak period, observations of parking area utilisation, observations of shopping centre occupancy and discussions of the possible reasons for differences between predicted and actual traffic volumes. Confirmation that the study is original and was carried out by myself and permission from Arcus Gibb (Ply) Ltd to use the study as part of my final-year project, is provided in Appendix A.

Thesis (MEng (Civil Engineering))--University of Stellenbosch, 1999. / 100 leaves single printed pages, preliminary pages and numberd pages 1.1-9.1.Includes bibliography. List of figures, tables, symbols and acronyms. Scanned with a HP Scanjet 8250 Scanner to pdf format (OCR). / ENGLISH ABSTRACT: A tropical cyclone is a non-frontal, synoptic scale, low-pressure system over tropical or subtropical waters with organised convection and a definite cyclonic surface wind circulation. The system varies in size between a hundred and a few thousand kilometres in diameter with high winds circulating around a central low pressure. The process of bringing the lower atmospheric layers into thermodynamic equilibrium with the warm tropical waters add the energy to the atmosphere and lower the surface pressure. If favourable climatic conditions exist this leads to the formation of a warm core vortex, which can develop into a tropical cyclone. The occurrence of tropical cyclones follows seasonal variations, the tropical cyclone season for the Southwest Indian Ocean being between November and March. The occurrences peak along the Southern African East Coast between Mid-January and Mid-February. The data on the location and intensity of tropical cyclones along the Southeast Africa coastline were obtained from the Joint Typhoon Warning Centre and span the period between 1848 and 1999. The available data before 1945 consist of tropical cyclone tracks that influenced populated areas or were encountered by ships. It was assumed that a number of tropical cyclones before 1945 were not recorded and therefore data collected before 1945 were disregarded in the analysis. The development of radar in 1945 significantly improved the detection of tropical cyclones. Some of the tropical cyclone tracks recorded between 1945 and 1956 contain information about the intensity of the tropical cyclone. Since the dawn of the satellite age in the mid 1980's, the detection of tropical cyclones and intensity measurements have improved vastly. Monte Carlo simulation techniques were used to create long term data series based on the available measured data. Statistical distributions were fitted for each characteristic describing the tropical cyclone at its nearest position to the site under investigation. Tropical cyclones frequently occur along the Southern African East Coast. The region where more than one tropical cyclone per 100 years can be expected is bordered by latitudes 2.5°S to 32.5°S. The design parameters for structures in these regions should provide for the influence that a tropical cyclone will have on the site. The occurrence rate and expected maximum intensity of tropical cyclones with a 1DO-year return period vary with latitude along the Southern African East Coast. The maximum number of tropical cyclones in a 1DO-year period occurs at latitude 15°S with an expected number of tropical cyclones of 157.2 per 100 years. The maximum expected tropical cyclone intensity in a 100-year period is 143.5 knots at latitude 17.5°S. / AFRIKAANSE OPSOMMING: Tropiese siklone is nie-frontale laagdrukstelsels wat hulle ontstaan het oor tropiese en subtropiese oseane. 'n Stelsel bestaan uit 'n sentrale laagdrukstelsel met sirkulerende winde daar om. 'n Sikloon se deursnee kan wissel van 'n honderd tot 'n paar duisend kilometer. 'n Laagdrukstelsel ontstaan as gevolg van 'n termodinamiese wanbalans tussen die atmosfeer en die warm oseaanwater in die trope. Indien die benodigde atmosferiese toestande heers kan die laagdrukstelsel in 'n tropiese sikloon ontwikkel. In die Suidwestelike Indiese Oseaan vorm tropiese siklone tussen November en Maart. Die meeste siklone kom hier voor vanaf middel Januarie tot middel Februarie. Data is verkry vanaf die "Joint Typhoon Warning Centre" vir die Suidwestelike Indiese Oseaan en strek vanaf 1848 tot 1999. Die data voor 1945 verteenwoordig slegs die tropiese siklone wat bewoonde areas of skeepsvaart beinvloed het. Daar is aangeneem dat 'n betekenisvolle getal van die tropiese siklone voor 1945 nie gedokumenteer is nie en derhalwe is slegs data van sikloon voorkomste na 1945 gebruik in die studie. Vanaf 1945 het die ontwikkeling van radar die opsporing van siklone in onbewoonde areas moontlik gemaak. Die gebruik van weersatelliete vanaf die middel 1980's het die kwaliteit van die data nog verder verbeter. Monte Carlo simulasie tegnieke is gebruik om langtermyn data vir spesifieke posisies langs die kus te genereer. Statistiese verdelings is gepas op die eienskappe wat die sikloon beskryf wanneer dit die naaste posisie aan die terrein bereik. Die passing van die verdelings is gedoen op die beskikbare historiese data. Die verdelings is dan gebruik om langtermyn data stelle te skep vir die terrein. Tropiese siklone kom gereeld in die Suidwestelike Indiese Oseaan voor en beinvloed die Suid-Afrikaanse Ooskus. Meer as een tropiese sikloon kan elke 100 jaar verwag word in kusgebiede tussen breedtegrade 2.5° S en 32.5° S. Die ontwerpe vir strukture in die gebied moet dus voorsiening maak vir die invloed van tropiese siklone. Die voorkoms en intensiteit van tropiese siklone varieer met breedtegraad langs die Suid-Afrikaanse Ooskus. Die meeste siklone word verwag by breedtegraad 15°S met 'n gemiddelde van 157.2 siklone per 100 jaar. Die mees intensiewe siklone kom voor by breedtegraad 17.5°S met 'n verwagte 1:100 jaar intensiteit van 143.5 knope.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2010. / Thesis presented in fulfilment of the requirements for the degree of Master of Science in Engineering at Stellenbosch University / ENGLISH ABSTRACT: Weigh-in-motion (WIM) scales are installed on various higher order South African roads to provide traffic loading information for pavement design, strategic planning and law enforcement using a scientific approach. The two most respected international guideline documents for WIM systems are the American ASTM E1318 Standard and the COST 323 European Specification, yet neither are fully suited to be applied to local WIM systems. The author developed a post-calibration method for WIM data, called the Truck Tractor (TT) Method, to correct the magnitude of recorded axle loads in retrospect. It incorporates a series of powerful data quality checks. The TT Method is robust, accurate and adequately simple to be used on a routine basis. The TT Method uses the truck tractor loads of articulated 6- and 7-axle trucks with single steering- and double driving axles – these vehicle are called Eligible Trucks. Only Eligible Trucks with average axle loads between 6.5 t and 8.5 t are used in the calibration process – these vehicles are called Selected Trucks. A calibration factor, kTT, is determined using a fully automated iterative procedure, and multiplied with all axle load measurements to produce data for which the average truck tractor load of Selected Trucks, TTT, is equal to 21.8 t. The TT Method can be used for WIMs in various operating environments and is not sensitive to the extent of miss-calibration of a WIM, clipping of sensors owing to poor lane discipline or different extents of loading on different routes. The TT Method includes a series of data quality checks that can be used on a routine basis. They are summarised as follows: - The standard deviation of truck tractor loads for Selected Trucks, STTT, should always be below 2.0 t, but preferably below 1.9 t. - The standard deviation of front axle loads for Selected Trucks, SFTT, should always be below 0.9 t, but preferably below 0.8 t. - The post-calibration factor from the TT Method, kTT, should be between 0.9 and 1.1. The factor for any month should not deviate by more than 3% from the moving average of the previous five months. - The average of front axle loads of Selected Trucks, FTT, should be between 5.6 t and 6.6 t; the exact values are influenced by load transfer between the steering and driving axles. - A procedure was formulated using the Front axle / Truck tractor Ratio, FTR, to identify the percentage of Eligible Trucks that in all probability clipped the sensor. The percentage of these records must be below 10 %, but preferably below 6 %. The TT Method has the potential to significantly improve WIM data collection in South Africa. The calibration module of the TT Method, i.e. the procedure to calculate kTT, has already been accepted by SANRAL. Most of the data quality checking concepts associated with the TT Method were also accepted, although their threshold values are still being refined. / AFRIKAANSE OPSOMMING: Weeg-in-beweging (“weigh-in-motion”, WIM) skale word op talle hoë orde paaie in Suid- Afrika gebruik om op wetenskaplike wyse verkeersinligting te verskaf wat gebruik word vir plaveiselontwerp, strategiese beplanning en wetstoepassing met betrekking tot oorlading. Nie een van die twee vooraanstaande internasionale riglyne vir WIM sisteme, die ASTM E1318 Standaard en die COST 323 Europese Spesifikasie, is in geheel geskik vir Suid-Afrikaanse kondisies nie. Die outeur het ‘n unieke kalibrasie metode, genaamd die TT Metode, ontwikkel wat ’n reeks roetine kwaliteitsbeheertoetse vir WIM data insluit. Die TT Metode is eenvoudig, akkuraat en toepaslik vir ’n wye verskeidenheid WIM sisteme in Suid-Afrika. Die massa van trekkers van geartikuleerde 6- en 7-as vragmotors met enkel stuur- en dubbel dryf-aste en ’n gemiddelde asmassa tussen 6.5 en 8.5 ton (ook genoem Geselekteerde Vragmotors) word as verwysingsmassa gebruik. ’n Iteratiewe prosedure word gevolg vir die bepaling van die kalibrasie faktor, kTT. Dieselfde faktor word met alle asmassas in die data vir die analise periode vermenigvuldig, met die einddoel dat die gemiddelde trekker massa van die Geselekteerde Vragmotors, TTT, gedryf word na die teikenwaarde van 21.8 ton. Die TT Metode is ewe toepaslik ongeag die tipiese belading van trokke op ’n roete, hoe goed die WIM sisteem oorspronklik gekalibreer was of hoe goed laandissipline by die WIM sensor is. Die kwaliteitsbeheertoetse kan op ’n roetine basis toegepas word as deel van die uitvoering van WIM kalibrasie prosedure, en word soos volg saamgevat: - Die standaard afwyking van trekker massas van Geselekteerde Vragmotors, STTT, behoort altyd laer as 2.0 ton, maar verkieslik laer as 1.9 ton te wees. - Die standaard afwyking van voor-as massas van Geselekteerde Trokke, SFTT, behoort altyd laer as 0.9 ton, maar vekieslik laer as 0.8 ton te wees. - Die kalibrasiefaktor, kTT, moet verkieslik tussen 0.9 en 1.1 wees, en mag nie met meer as 3 % van die gemiddelde kTT vir die voorafgaande vyf maande verskil nie. - Die gemiddeld van voor-as massas van Geselekteerde Vragmotors, FTT, behoort tussen 5.6 ton en 6.6 ton te wees. Die presiese waarde hang af van die mate waartoe gewig tussen die voor-as en dubbel dryf-as oorgedra word weens dinamiese effekte op die trekker. - Die verhouding tussen die voor-as en dubbel dryf-as, bekend as die FTR, kan gebruik word as ‘n aanduiding of ’n trok weens swak laandissipline slegs gedeeltelik oor die WIM sensor gery het. Die persentasie gedeeltelike metings moet laer as 10%, maar verkieslik laer as 6 % wees. Die TT Metode het die potensiaal om die insameling en kwaliteit van verkeersdata deur middel van WIM sisteme noemenswaarding te verbeter. Die kalibrasie module van die TT Metode, m.a.w. die prosedure om kTT te bereken, is reeds deur SANRAL aanvaar. Die meeste van die kwaliteitsbeheerkonsepte wat met die TT Metode gepaard gaan is ook aanvaar, maar die drempelwaardes hiervoor word nog verfyn.