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Critical normal traffic loading for flexure of bridges according to TMH7Malan, Andreas Dawid 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Different types of live loading due to traffic may act on bridges. The focus of this study is on
normal traffic loading according to the South African specification of TMH7. Heavy vehicles are not
included in normal traffic loading. TMH7 represents the code of practice for the design of highway
bridges and culverts in South Africa. The aim of the study is to provide an insight into the
flexural
analysis of skew bridges, under the effects of normal traffic loading.
The need for the study arose since the specification of TMH7 does not explicitly specify application
patterns for normal traffic loading. Only the intensity of normal traffic loading is specified and it
should be applied to yield the most adverse effects. For these reasons, a set of so-called standard
application patterns are investigated and developed through the course of this study. The envelope
of the values from the standard application patterns are compared to the most adverse application
pattern for
flexural effects in certain design regions of the bridge deck. Flexure, as in the context of
this study, translates into the bending and twisting of the bridge deck under loads.
A number of numerical experiments are performed for typical single span and multi-span
continuous carriageways, where the standard application patterns are compared to the most adverse
application patterns. The results from the numerical experiments are documented and compared as
the angle of skew of the bridge deck increases in plan-view. For this purpose, the development of
effective and specialized software was necessary.
It was found that the set of standard application patterns can be used as a preliminary approximation
for the most adverse effects of normal traffic loading, for specific
flexural resultants in certain
design regions of a bridge deck. However, for a large number of secondary
flexural effects, the set of
standard application patterns did not represent a good approximation for the most adverse values. / AFRIKAANSE OPSOMMING: Verskillende tipes lewendige belasting, as gevolg van verkeer, kan op brûe inwerk. Die fokus van
die studie is op normale verkeers-belasting volgens die Suid-Afrikaanse spesifikasie van TMH7.
Swaar-voertuie word nie ingesluit by normale verkeers-belasting nie. TMH7 verteenwoordig die kode
vir die ontwerp van padbrûe en duikers in Suid-Afrika. Die doel van die studie is om insig te verskaf
in die buig-analise van skewe brûe, as gevolg van die werking van normale verkeers-belasting.
Die rede vir hierdie studie ontstaan aangesien die spesifikasie van TMH7 nie eksplisiet aanwendingspatrone
vir normale verkeers-belasting voorskryf nie. Slegs die intensiteit van normale verkeersbelasting
word voorgeskryf en dit moet aangewend word om die negatiefste effekte te verkry. Vir
hierdie redes word 'n versameling van sogenaamde standaard aanwendings-patrone deur die loop van
die studie ondersoek en ontwikkel. Die omhullings-kurwe van die waardes wat deur die standaard
patrone gelewer word, word vergelyk met die waarde van die aanwendings-patroon wat die negatiefste
buig-effek in sekere ontwerp-areas van die brugdek veroorsaak. Buig-effekte, soos van toepassing op
hierdie studie, verwys na buig en wring van die brugdek as gevolg van belastings.
'n Aantal numeriese eksperimente, vir enkel-span sowel as multi-span deurlopende brugdekke,
word uitgevoer en die standaard aanwendings-patrone word vergelyk met die aanwendings-patrone
wat die negatiefste waardes lewer. Die resultate van die numeriese eksperimente word gedokumenteer
en vergelyk soos die hoek van skeefheid van die brugdek in plan-aansig toeneem. Vir hierdie doel is
die ontwikkeling van effektiewe en gespesialiseerde sagteware dus nodig.
Daar is gevind dat die standaard aanwendings-patrone, vir spesifieke buig-resultante in sekere
ontwerp-areas van die brugdek, as 'n voorlopige benadering vir die negatiefste effekte van normale
verkeers-belasting gebruik kan word. Dit was egter verder gevind dat vir 'n groot aantal sekondêre
buig-effkte, die versameling standaard aanwendings-patrone nie as 'n goeie benadering vir die
negatiefste waardes dien nie.
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Non-linear overload behaviour and ductility of reinforced concrete flexural members containing 500MPa grade steel reinforcementGravina, Rebecca Jane. January 2002 (has links) (PDF)
Includes corrigenda (inserted at front) and list of publications published as a result of this research. Includes bibliographical references (leaves 192-199) Investigates the overload behaviour and modes of collapse of reinforced concrete flexural members containing 500MPa grade reinforcing steel and evaluates the adequacy of current ductility requirements for design according to AS 3600 to ensure strength and safety.
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Non-linear overload behaviour and ductility of reinforced concrete flexural members containing 500MPa grade steel reinforcement / by Rebecca Jane GravinaGravina, Rebecca Jane January 2002 (has links)
Includes corrigenda (inserted at front) and list of publications published as a result of this research. / Includes bibliographical references (leaves 192-199) / xxvii, 223 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the overload behaviour and modes of collapse of reinforced concrete flexural members containing 500MPa grade reinforcing steel and evaluates the adequacy of current ductility requirements for design according to AS 3600 to ensure strength and safety. / Thesis (Ph.D.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2002
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Análise da vida útil estimada das edificações baseada na norma de desempenho (ABNT NBR 15.575:2013)Silva, Nina Celeste Macario Simões da 25 February 2016 (has links)
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Previous issue date: 2016-02-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Analysis of service life of a building requires the observation of many variables, especially corre-lating to the performance and durability. In this meaning, the NBR 15.575:2013 - Residential Buildings - Performance establishes requirements, criteria and methods assessment for analyz-ing the performance of buildings, and sometimes subsidize designers to determine the design life consistent with the performance level desired by the builder and user. Adding that the calculation of the estimated service life of buildings takes into account the natural aging of the building sys-tems components, but not contemplates of the damage effect caused by the entry into operation and use of the building or absence conservation. Moreover, the NBR 5.674:2012 - Buildings Maintenance - Requirements for the maintenance management system, indicates which systems and services that must go through the maintenance process and in what period, enabling mainte-nance management quality. However, it is not always what happens in the buildings after entry into operation and use. In the survey, we tired so verify the relationship between the predicted service life and the warranty period of the building. The information analyzed were provided by an active construction of Recife, collected in a database from the technical assistance after work eight buildings in the Metropolitan Region of Recife. To measure the percentage difference be-tween the design life and estimated service life, following the intervention of the technical assis-tance after work was used the factors method set out in ISO 15.686:2000 - Building and construc-tion assets - Service life planning and recommended by NBR 15575-1:2013. The frequency of occurrence damage in buildings was analyzed by determining the rates of failure in the buildings. The results show to a reduction of the design life of the order of 20% of the reference service life, from values adopted in the Performance of Brazilian Standard; also point to a concentration of damage in the initial stage of construction, above 50%, which correlate with the conditional prob-ability of failure curve (Bathtub Curve) sorting a high abrupt failure rate, ranking the building at the stage of infant mortality. These results reflect an unplanned variation in performance level proposed for the building. In this context, it is suggested to link the period of the works guarantee to the level of actual performance of the building. The application of reliability concepts allows infer about warranty period of the Building and make comparisons with the requirement of Brazi-lian law enforcement. / A análise da vida útil (VU) de uma edificação exige a observação de muitas variáveis, especialmente aquelas voltadas para o desempenho e durabilidade. Nesse sentido, a ABNT NBR 15.575:2013 Edificações habitacionais Desempenho estabelece requisitos, critérios e métodos de avaliação para analisar o desempenho das construções, e ao mesmo tempo subsidiar os projetistas a determinar a vida útil de projeto (VUP) condizente com o nível de desempenho desejado pelo construtor e usuário. Acrescente-se que o cálculo para a vida útil estimada (VUE) das construções leva em consideração o envelhecimento natural dos componentes dos sistemas construtivos, mas não contempla o efeito dos danos provocados pela entrada em operação e uso da edificação ou ausência de manutenção. Além disso, a ABNT NBR 5674:2012 - Manutenção de edificações Requisitos para o sistema de gestão de manutenção, indica quais os sistemas e serviços devem passar pelo processo de manutenção e em qual período, possibilitando a gestão da manutenção com qualidade. Entretanto, não é sempre o que ocorre nas edificações após a entrada em operação e uso. Na pesquisa, procurou-se, então, verificar qual a relação entre a vida útil estimada e os prazos de garantia das obras. Para medir a diferença percentual entre a VUP e a VUE, após a intervenção da ATPO foi utilizado o método dos fatores previsto na ISO 15.686:2000 - Building and construction assets service life planning e recomendado pela NBR 15.575-1:2013. As informações analisadas foram cedidas por uma construtora atuante na cidade do Recife, coletadas de um banco de dados proveniente da assistência técnica pós-obra (ATPO) de oito empreendimentos construídos na Região Metropolitana do Recife. A frequência de ocorrência de danos nas edificações foi analisada através da determinação da taxa de falhas dos empreendimentos. Os resultados assinalam para um percentual de redução da vida útil de projeto (VUP), da ordem de 20% da vida útil de referência (VUR), valores adotados da NBR 15.575:2013; apontam também, para uma concentração de avarias no estágio inicial da construção, acima de 50%, que correlacionando com a curva de probabilidade condicional de falha (curva da banheira) obtém-se um alto índice de falha brusca, classificando a edificação na fase da mortalidade infantil. Esses resultados refletem uma variação não planejada do nível de desempenho proposto para a edificação. Diante desse contexto, sugere-se vincular o prazo de garantia da obra com o nível de desempenho efetivo da construção. A aplicação de conceitos de confiabilidade permite inferir sobre os prazos de garantia da obra e fazer comparações com o valor previsto no aparato legal brasileiro.
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Återbruk av betongbjälklag från miljonprogrammet : Användningen av gamla bjälklag från lamellhus i nya projekt / Reuse of concrete joists from the million programmeHolmberg, Henrik, Zeinal, Nor January 2023 (has links)
Det blir idag allt viktigare att tänka hållbart, inte minst inom byggbranschen. Klimatmål, ekonomi och resursförbrukning är en del av de faktorer som bidrar till att branschen måste styras mot ett cirkulärt förhållandesätt. Det finns en potential i de stora mängder flerbostadshus från miljonprogrammet som planeras att byggas om eller rivas. Det saknas dock praktiska lösningar på hur detta görs, det saknas även kunskap samt kompetens inom återbruk. Denna undersökning kommer att utreda hur en ny byggnad kan konstrueras med återbrukad betong kombinerat med KL-trä, genom att analysera strategier för demontering, förband samt ta fram konstruktionslösningar. Studien innehåller en metoddel där beräkningar och programvara beskrivs, en teoridel där strategier för demontering, montering och förband samlats in. Resultatet presenterar de konstruktionslösningar som tagits fram samt resultatet av beräkningar som gjorts, slutsatsen blev att konstruktionen håller med hänsyn till bärighet. I diskussionen skriver författarna om möjliga strategier för återbruk och de metoder och resultat som erhållits. Författarna diskuterar även kring social hållbarhet och cirkulär ekonomi. / Sustainable thinking is becoming increasingly important, not least in the construction industry. Climate targets, economy and resource consumption are factors that contribute to the need to steer the industry towards a circular approach. There is potential in the large number of apartment buildings from the Million Programme that are planned to be rebuilt or demolished. However, there is a lack of practical solutions on how to do this, as well as a lack of knowledge and expertise in reuse. This study will investigate how a new building can be constructed with recycled concrete combined with CLT, by analyzing strategies for dismantling, joints and developing design solutions. The study contains a method where calculations and software are described, a theory where strategies for disassembly, assembly and connections are collected. The result presents the design solutions that have been developed and the results of the calculations made, the conclusion was that the design works with regard to load bearing capacity. In the discussion, the authors write about possible strategies for reuse and the methods and results obtained. The authors also discuss social sustainability and circular economy.
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Evaluating the quality of the national government self-help housing scheme in the Western Cape; before and after NHBRC involvementMayongo, Nwabisa January 2018 (has links)
Thesis (MTech (Business Administration in Project Management))--Cape Peninsula University of Technology, 2018. / According to Section 26 (1) of the constitution of Republic of South Africa, everyone has a right to have a satisfactory house to restore and honour the dignity of the South Africans. However South African government implemented several housing programmes to bridge the gap of housing backlog in South Africa. One of the housing programmes that South African government implemented is People Housing Process (PHP). It was approved in 1998 by South African government. South African government shifted focus on the quality of houses and mainly focused on the quantity of houses delivered through the financial year. There have been a lot of quality complaints on PHP. The quality defects are signs of foundation failures, cracks on foundations, water flooding around the houses, water not properly channelling to the drain, cracks on walls, dampness of walls, mould on walls, water seeping through the windows, poorly applied external plaster, incorrect bonding of internal walls to external walls, walls that are not straight walls, sagging ceiling panels, gable not properly filled with mortar, roof structure not properly tied up, sagging roof coverings, roof leaks, sagging roof tiles and ridges, rust on painted iron material, poor quality of blocks used, insufficient cement on mortar mix and peeling off paint. National Home Builders Registration Council (NHBRC) are the custodians of the home building industry. They were excluded from PHP from 1998 till March 2012. NHBRC was approved to inspect PHP house in April 2012. Thus, the aim of the study was to compare the houses that were built before NHBRC involvement in PHP with those that were built after NHBRC involvement in PHP. The sample included 50% of each of the two groups (those in houses built without NHBRC involvement and those built with NHBRC involvement), the research involved at least 50 respondents per group (McMillan, et al 2001:177 – recommends 15 respondents per group). The sample size per group has been put at 50 since the larger the sample the higher the accuracy. The study is classified as quantitative research because it intended to quantify the variation in occurrence, situation, problem or issue; the information was gathered using predominantly quantitative variables and the analysis was geared to ascertain the magnitude of the variation. The findings of the study revealed that the quality of the houses that were built under PHP programme before NHBRC intervention on PHP was not up to standard however the quality on those that were built after NHBRC involvement improved. Therefore it is recommended for Western Cape government to implement the rectification programme which was approved by National Department of Human Settlements in 2009 mainly focusing on houses that have been severely structurally compromised and are regarded as unfit for human habitation as it poses a threat to the health and safety of the occupants (The National Housing Code, 2009: 11-13).
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