abstract
Universidade de Aveiro Departamento de Engenharia Civil
2009Strategies and methodologies for urban rehabilitation interventions
This dissertation approaches the subject of renewal and urban rehabilitation, for which the technical and scientific sphere have been progressively alert and conscientious. The contribution of this work begins with the reflection and framework of the actual tendencies of urban rehabilitation actions in our Country, with the development of a model that allows the identification of several competitive actions within the process. Once identified problems, strengths, difficulties and opportunities, it is possible to define a strategy with the goal of guiding actions and processes on rehabilitation in a sustainable manner.
In the development of proposals and definition of urban rehabilitation strategies is fundamental to carry out a thorough inspection and diagnosis, appropriate to the scale of the area under analysis. It is proposed a procedure, to register and diagnose the conservation state of the buildings, tested and applied in the process of Urban Renewal of the Historical City Centre of Coimbra, attending to several partial goals. The structured and reliable diagnosis task for the constructive characterization of the buildings of old urban centres, their degradation conditions and most significant defects, has allowed the creation of a database of relevant information on the old building stock of this area of the city, that provides, not just direct results from simple queries regarding the buildings, the architecture and other socio-demographic aspects. It also allows supporting other studies, with resource to models and more sophisticated analyses, for which will result indicators and insightful results, as for example, concerning the evaluation of structural safety and building vulnerability.
It is also presented results of a in-situ testing campaign to collect further data on the mechanical characterization and behaviour of masonry using flat-jack testing techniques, specifically on the compressive stress state, and other mechanical properties (deformability, compressive strength and Young modulus) fundamental information when analyzing old buildings.
In the last decades the evaluation of the seismic risk, just as other natural phenomenon’s, are of rising concern, considered essential in the activity and definition of strategy planning and urban management. The evaluation of the seismic vulnerability of the existent building stock in the perspective of the seismic risk mitigation should not be placed only in relation to the isolated buildings of relevant historical and cultural importance, but also, in relation to the agglomerate of buildings in urban centres. The analysis of building performance in recent earthquakes, has allowed identifying the structural aspects that mainly influences in their vulnerability, and consequently in the occurrence of damage mechanisms. The results of evaluation of the vulnerability will be presented in accordance to a new proposed methodology based on a vulnerability index that consequently allows the evaluation of damage and creation of loss scenarios (economical and human). It will be discussed and evaluated the application of the proposed methodology and its integration in an SIG platform.
It was also developed simplified mechanical models, that through an non-linear analysis, evaluate the vulnerability of isolated buildings and building aggregates (group of buildings), discussing aspects associated to he uncertainty in the definition of the structure capacity, and in the identification of the structural performance and response of structures. The results produced are confronted with the methodology based on the vulnerability index.
Two numerical models were also developed, with two aims: to analyze different retrofitting and repair strategies and to confront the results produced with the mechanical model. This way it is discussed with different levels of detail, the approaches for vulnerability evaluation, presentation and interpretation of the results, associated necessarily to its operative scale.