Comparison between Eurocodes and UK standards (BDs) for structural assessment. The Case Study of Ashworth Viaduct

• Autor(a) principal: Monteverde, Marta Luísa de Lima
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/31895
• topic: structural assessment; composite bridges; structural strengthening; Eurocodes; BDs; Comparison between Eurocodes and BDs; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Civil

Within the scope of safety and preservation of historical memory of existing bridges, maintenance of bridges has become one of the most important issues to the economy, society and public interest. To achieve this objective, an efficient management of bridges is needed, being implied in the process, periodic inspections and structural assessments, followed by repair, rehabilitation or strengthening, if necessary. However, drastic actions, such as demolition and/or substitution have to be considered when the structure does not accomplish the minimum requirements of the new standards or it is not economically viable for any other intervention. This work concentrates on an essential aspect within the process of maintenance, which is the structural assessment of existing bridges. Therefore, an approach regarding this subject is carried out using two different methods of assessment, one based in the Eurocodes and the other one guided by the UK standards for structural assessments, having as the main aim the comparison of these two standards. To better understand the evolution of bridges in the United Kingdom, a historical approach is developed as first contact, highlighting the beginning of great constructions in history, using as material construction, steel, concrete and steel-concrete composite. It is known that bridges have been through great changes in traffic load over time affecting thus, their maintenance and the need for structural assessment. On one side’ this came to encourage the UK in creating unique standards made specifically for structural assessment (BDs) of bridges. On the other side, the Eurocodes, despite having been created specifically for design of new bridges, are adapted to the assessment of existing bridges, being used in many other countries around Europe. Throughout this work, the main differences between these two standards, mentioned above, are described taking into account the actions applied on bridges, the used partial safety factors, the properties and capacity of construction materials and the effects of the actions observed in the structural members. To support this comparison, it is also introduced a composite viaduct existing in the UK, where it is possible to take the distinct results from the different models of forces acting on the structure. In conclusion, an analysis of the two results is carried out in order to register the difference between both codes and discuss main features for future structural assessment works. BDs has been registered to be more conservative than Eurocodes although the results between them do not show a high discrepancy.