Strategies for building pathology reports in an urban rehabilitation process: Project of the Old City Centre of Coimbra

The increasing interest on architectural heritage associated to the recognised building value, at economic, social and cultural levels have stimulated, in the recent decades, the urban rehabilitation and renovation o several cities in Europe. Despite the strategy or method adopted in a city renovation process, its efficiency depends mainly on: type of buildings (structural systems, construction techniques and materials); intervention level (singular buildings, groups of buildings, urban zones, etc.); and, project objective (risk assessment, decision making to support future rehabilitation projects, definition of council maintenance policies, etc.). In what concerns large renovation programs of old city centres, choosing the most adequate approach for inspection, appraisal and diagnosis is a complex task that can determine the success or failure of the project purpose. This paper describes the preparation phase of the inspection of 700 buildings located in the old city centre of Coimbra (Portugal), where a global renovation process is planned for the forthcoming years. In the scope of the renovation and rehabilitation process, the city council contract a complete identification and inspection survey of the buildings, directed on three different domains: (a) architectural typologies, (b) constructive and pathological condition of buildings, and (c) socio-demographic characterisation, of this part of the city. It will be present the check-lists developed and some of the obtained results on point (b), related to roofing systems, and exterior façades. This diagnosis procedure shows that the inspection results quality is quite dependent on the items surveyed for each construction element (roof, façade, internal members, installation efficiency), as well as on the possibility of their correlation for a single building. The adopted method has been applied on 70% of the buildings inspected within the project perimeter. Further treatment of the inspection and appraisal data will allow the developing pathology reports and list repair actions, and estimating rehabilitation costs. It will also help to produce defect level diagrams and seismic building risk maps, but, most important, to improve and guide a renewal strategy and intervention methodology for old buildings

Seismic vulnerability assessment of the old city centre of Seixal, Portugal

The seismic vulnerability assessment of old traditional masonry building stocks, in a seismic risk mitigation perspective, is truly essential not only for buildings with recognized historical and patrimonial value, but also, in relation to regular buildings. In this sense, this paper approaches the issue of the seismic vulnerability assessment of masonry buildings through the application of a simplified methodology to building stock of the old city centre of Seixal, Portugal. This methodology is based on a vulnerability index, suitable in the evaluation of damage and in the creation of large scale loss scenarios (economical and human). Over 500 buildings were evaluated in accordance with the referred methodology and the results obtained were then integrated into a Geographical Information System tool. The integration of this kind of vulnerability and loss results into a GIS tool allows that city councils or regional authorities make their decisions based on a global view of the site under analysis, which led to more accurate and faster decisions either in terms of risk mitigation strategies or rehabilitation plans. This tool can also assumes great importance in the construction of safety and rescue plans

Vulnerability assessment of urban building stock: a hierarchic approach

In the last decades the evaluation of the seismic risk 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 chronological construction process frequently results in characteristic heterogeneity of masonry and wall connection quality. In addition, buildings do not constitute independent units given that they share the mid-walls with adjacent buildings and the façade walls are aligned. This way, as post-seismic observations proved, buildings do not have an independent structural behaviour, but they interact amongst themselves, mainly for horizontal actions and so the structural performance should be studied at the level of the aggregate and not only for each isolated building. In most cases, for masonry structures there is no need for sophisticated dynamic analyses for seismic resistance verification or vulnerability assessment. This is even more relevant when an assessment at the level of a city centre is pursued. In this work, the results of evaluation of the vulnerability will be presented in accordance to three proposed methodologies based on a vulnerability index that consequently allows the evaluation of damage and creation of loss scenarios (economical and human) not only at the level of the building and its façade walls but also at the level of the aggregates. It will be discussed and evaluated the application of the referred methodologies and its integration in an SIG platform

Evaluation of strengthening techniques of traditional masonry buildings: case study of a four-building aggregate

Increasing appraisal of the durability, conservation state, and changeable use and function of old buildings in urban centers relies a great deal on the structural safety evaluation of vertical load capacity and the ability to resist horizontal forces. The need to assess seismic vulnerability, particularly of traditional masonry buildings, is a key issue. Evaluation of the seismic vulnerability of old buildings is essential in the definition of strengthening needs and minimization of damage from seismic actions in the safeguarding of built heritage. A three-dimensional model was developed for an aggregate of four traditional masonry buildings located in the old city center of Coimbra, in Portugal. The finite element modeling of these buildings has aimed to identify structural fragility, understand the damages detected, and evaluate the global structural safety of these types of buildings. The primary results obtained in this case study helped to interpret the structural damage and stress distribution, and verified global stability and its consequences. Different strengthening techniques to improve the global behavior of these buildings were modeled and analyzed. A comparison of the efficiencies of strengthening strategies is also discussed. DOI: 10.1061/(ASCE)CF.1943-5509.0000164. (C) 2011 American Society of Civil Engineers

Inspection and appraisal of old buildings: building defect reports for the rehabilitation process

The increasing concern and knowledge on architectural heritage have been, in the recent decades, serious reasons for urban rehabilitation and renovation processes. There are many strategies and methods to systematize various tasks in a city renovation process, which efficiency depends mainly on the type of buildings (structural schemes and techniques, type of construction materials), on the type of global project approach (singular buildings, groups of buildings, urban intervention zones, etc.) and on the exact final purpose (risk assessment and decision making, future rehabilitation projects, definition of a council maintenance policy, etc.). In what concerns large renovation programs of old city centres, choosing the most adequate approach for inspection, appraisal and diagnosis is a complex task that can determine the success or the total failure of the project purpose. This paper describes the procedure used for the inspection of 700 buildings located in the old city centre of Coimbra (Portugal). A complete identification and inspection survey was carried out for all of the buildings on three different domains: (a) architectural typologies, (b) constructive typology, building defects, conservation state, and (c) socio-demographic characterization. All the data gathered was recorded for each building and connected with a SIG application, as well as with a relational database, in order to have a deeper and interdisciplinary knowledge of the project perimeter and hence to be able to manage the historical building stock. In this paper will be presented the building check-lists developed for inspection, the building defect reports produced for the rehabilitation and renewal process. It will be presented the overall results from the inspection survey for different construction elements that allowed the characterization of traditional construction solutions and diagnosis of the most common defects for these type of buildings

Anomalias estruturais correntes em edifícios antigos

Neste artigo é caracterizada a construção dos edifícios antigos, particularmente da Baixa de Coimbra. Esta caracterização é essencialmente feita pela identificação das soluções e tecnologia construtiva ao nível da estrutura resistente, isto é do “esqueleto” dos edifícios antigos: paredes de alvenaria e estruturas de madeira (pavimentos e coberturas). Observa-se a utilização sistemática de materiais tradicionais como a madeira em estruturas de pavimento e de cobertura; pedra calcária em paredes de fachada e em guarnições de aberturas; areia do rio e cal em argamassas de enchimento e rebocos; e barro, nos diversos tipos de telha e em alguns elementos de alvenaria. Para além da caracterização construtiva é feita o levantamento das anomalias estruturais mais comuns, constituindo um catálogo das anomalias mais relevantes dos edifícios antigos da Baixa de Coimbra

Vulnerability assessment of traditional buildings in Coimbra, Portugal, supported by a GIS Tool

The increasing concern and consequent appraisal on durability, conservation state and change of use of old buildings in urban centres is greatly related with structural safety assessment, particularly to seismic actions. It is largely recognised that the seismic vulnerability of the majority of historical city centres, with buildings without adequate seismic capacity, is high. The need to catalogue buildings according to their seismic vulnerability, particularly traditional buildings, is a key issue in any renewal or rehabilitation process. Recently, different methods for seismic vulnerability assessment have been proposed, with different levels of detail. Research carried out on seismic vulnerability have underlined that the performance of traditional buildings under earthquake actions is governed by several structural features, some of which can be peculiar of each urban context and construction technology. Seismic vulnerability assessment extended to whole historic centres has outlined the importance of GIS mapping applications in order to aid in the intervention and risk management plans. The need for an integrated multi-purpose tool, connected with a GIS, as well as with a relational database, in order to have a deeper and interdisciplinary knowledge of the site and hence to be able to create a modular approach and manage the historical building stock, conservation works, retrofitting strategy, risk assessment, building characteristics and vulnerability, damage and cost estimation is essential. In this paper, it is presented and discussed the strategy and methodology adopted for the vulnerability assessment of the city centre of Coimbra, in Portugal, through the GIS mapping of the building stock of the project perimeter. Development of vulnerability studies in urban centres can be conducted aiming to identify building fragilities and to reduce the seismic risk

Nonlinear dynamics within macroeconomic factors and stock market in Portugal 1993-2003

The main objective of this paper is to assess how mutual information as a measure of global dependence between stock markets and macroeconomic factors can overcome some of the weaknesses of the traditional linear approaches commonly used in this context. One of the advantages of mutual information is that it does not require any prior assumption regarding the specification of a theoretical probability distribution or the specification of the dependence model. This study focuses on the Portuguese stock market where we evaluate the relevance of the macroeconomic and financial variables as determinants of the stock prices behaviour

Avaliação numérica de soluções de reforço para edifícios antigos

O interesse e necessidade de avaliar diferentes soluções de reforço, particularmente para construções tradicionais de alvenaria sob acção sísmica é fundamental na definição de estratégias de reforço e medidas de minimização de dano na salvaguarda do património de valor cultural e histórico. Apresentaremos os principais resultados obtidos de uma modelação numérica de um agregado estrutural composto por quatro edifícios dispostos em banda. Três técnicas de reforço e reabilitação para melhorar o comportamento global deste conjunto de edifícios foram modelados e analisados. A eficiência destas estratégias é discutida em termos de controlo de deformação e análise custo-benefício. Pretende-se contribuir para a promoção das acções de recuperação e reabilitação de edifícios antigos integrados em zonas históricas. Após uma descrição e caracterização construtiva das alvenarias de pedra calcária e dos outros elementos construtivos e das suas principais características, destaca-se a análise feita em termos de deformações e tensões instaladas, de forma a melhor compreender o seu comportamento destes edifícios, e ainda, identificar as acções de intervenção a realizar e a sua compatibilização, com a escolha adequada de técnicas e materiais, que influenciem de forma positiva, pela posterior valorização da construção em termos de autenticidade arquitectónica, histórica e cultural