Rui Maio

Seismic vulnerability of building aggregates through hybrid and indirect assessment techniques

This work approaches the seismic vulnerability assessment of an old stone masonry building aggregate, located in San Pio delle Camere (Abruzzo, Italy), slightly affected by the 2009 April 6th earthquake occurred in L’Aquila and its districts. This building aggregate has been modelled by using the 3muri® software for seismic analysis of masonry constructions. On one hand, static non-linear numerical analyses were performed to obtain capacity curves together with the prediction of damage distributions for the input seismic action (hybrid technique). On the other hand, indirect techniques, based on different vulnerability index formulations, were used for assessing the building aggregate’s behaviour under earthquake action. The activities carried out have provided a clear framework on the seismic vulnerability of building aggregates, as well as aid future retrofitting interventions.

Seismic vulnerability assessment of historical urban centres: case study of the old city centre of Faro, Portugal

The necessity of implementing seismic vulnerability assessment procedures to the Portuguese building stock has become urgent as recent predictions indicate the possibility of the occurrence of an earthquake similar to the well-known 1755 Lisbon earthquake within the next 50 years. Obviously, at first instance, large-scale procedures should be used rather than more extensive and accurate methodologies suited for individual buildings assessment. Moreover, it is fundamental to operate in the most vulnerable areas in our built environment, typically, the historical urban centres. As it is recognised, it is within these areas, that old masonry buildings are generally concentrated, being both the most representative and vulnerable constructive typology. Comprising 354 buildings, the case study of the old city centre of Faro is herein presented aiming at analysing and evaluating the seismic vulnerability of its old masonry building stock. In order to achieve these objectives, a vulnerability-index-based methodology was used for the assessment of the seismic vulnerability of the old masonry buildings belonging to the historical centre of Faro (Ribeirinha area) carried out through detailed inspection and survey. The results obtained were analysed using a geographical information system tool. The integration of such vulnerability and loss results represents a valuable tool for city councils and/or regional authorities to plan interventions, on the basis of a global view of the site under analysis, leading this way to more accurate and comprehensive risk mitigation strategies which comply with the requirements of safety and emergency planning. The application of this large-scale scoring methodology has confirmed moderate-to-high values for the vulnerability of this particular area, which combined with its high seismicity, may be quite alarming.

Seismic vulnerability assessment of the old city centre of Horta, Azores: calibration and application of a seismic vulnerability index method

The seismic vulnerability assessment of old masonry buildings is essential not only to buildings with recognised historical and heritage value but also to ordinary residential masonry buildings. Thus, and resorting a wide set of damage data collected after the 1998 Azores earthquake, this paper addresses the topic of the seismic vulnerability assessment of traditional masonry buildings through the calibration and application of a simplified vulnerability assessment method to the old city centre of Horta (Faial Island), in Portugal. In this case study, 192 buildings were assessed using this methodology, and vulnerability and loss scenarios were analysed using an integrated Geographical Information System tool. As is discussed in this paper, such procedure could allow city councils or regional authorities to plan interventions based on a global view of the site under analysis, leading to more accurate and comprehensive risk mitigation strategies, which can than support the requirements of safety and emergency planning.

Analysis of the impact of large scale seismic retrofitting strategies through the application of a vulnerability-based approach on traditional masonry buildings

The buildings’ capacity to maintain minimum structural safety levels during natural disasters, such as earthquakes, is recognisably one of the aspects that most influence urban resilience. Moreover, the public investment in risk mitigation strategies is fundamental, not only to promote social and urban and resilience, but also to limit consequent material, human and environmental losses. Despite the growing awareness of this issue, there is still a vast number of traditional masonry buildings spread throughout many European old city centres that lacks of adequate seismic resistance, requiring therefore urgent retrofitting interventions in order to both reduce their seismic vulnerability and to cope with the increased seismic requirements of recent code standards. Thus, this paper aims at contributing to mitigate the social and economic impacts of earthquake damage scenarios through the development of vulnerability-based comparative analysis of some of the most popular retrofitting techniques applied after the 1998 Azores earthquake. The influence of each technique individually and globally studied resorting to a seismic vulnerability index methodology integrated into a GIS tool and damage and loss scenarios are constructed and critically discussed. Finally, the economic balance resulting from the implementation of that techniques are also examined.

Urban Fire Risk: Evaluation and Emergency Planning

Abstract The management, prevention and mitigation of urban risks are assumed as priority actions within the framework of any rehabilitation and requalification process at the urban scale, particularly in the case of the rehabilitation and refurbishment of old city centres. In the most specific domain of urban safety, seismic and fire risk, which can cause serious consequences, are part of the collective memory of several communities and must be inevitably highlighted. The severity of the resulting damages is a more than valid reason to strongly value prevention, planning and mitigation strategies, limiting their consequences and guaranteeing permanent improvement actions. In the view of the abovementioned, and in the scope of a research project carried out, a new urban fire risk assessment methodology was developed and applied to the old city centre of Seixal. This simplified methodology is based on a preestablished method designated ARICA. Over 500 buildings were assessed using this methodology, and the results were spatially analysed using an integrated geographical information system tool (GIS). It is worth noting that the integration of the risk results into a GIS platform is a valuable step towards the risk mitigation at a urban scale, allowing city councils or regional authorities to plan interventions on the basis of a global spatial view of the site under analysis leading to more accurate and comprehensive risk mitigation strategies that support the requirements of safety and emergency planning in case of urban fire.

Seismic Risk at the Urban Scale: Assessment, Mapping and Planning☆

Abstract In the last decades the evaluation of the seismic risk is 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 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 residential buildings within old urban centers. When assessing the seismic vulnerability of buildings it is essential to first establish the project objectives, before subsequently choosing the most appropriate strategy and tools necessary for building assessment and fulfillment of these objectives. It is also extremely important to understand the difference between the detailed approaches used for individual building assessment and those methods most efficient for larger scale analysis, pursued for city center assessment. In this work, the results attained from the vulnerability assessment of the old city center of Faro, in Portugal, allowed the estimation of physical damage scenarios, economical and human losses. The methodology applied herein and results are presented resourcing to a GIS application and database management system, enabling the storage of building features and survey, seismic vulnerability and risk mapping, as well as the continued upgrading and improvement of the collected data.

Awareness, Perception and Communication of Earthquake Risk in Portugal: Public Survey☆

Risks are associated to dangerous events that have an estimable probability of occurring and some potentially severe consequences. A risk is the potential to cause crisis, an emergency, a disaster and/or a catastrophe. The definition of risk acceptability is not technical but value driven. This definition is determined at two levels: at the individual level and at the state level. Every citizen decides what kind of risk he is willing to take in his daily life (his choice of transportation, his choice to smoke or to drink alcohol, etc.). The government, on the other side, is setting risk acceptability limits on a societal level (example: speed limits, laws regulating construction areas and density, etc.). The historical experience of a society will affect the way that it view risks and crisis. This article deals with seismic risk perception and communication in Portugal. A survey carried out resourcing to a questionnaire was developed to assess the knowledge on seismic risk perception and awareness in the Algarve region. Two questionnaires were developed: i) General Public, ii) Professional and Technical (engineers and architects). Results were treated statistically and thoroughly analysed and commented. Risk communication can influence communities to become aware of risks and it has a powerful influence on peoples risk decision-making and behaviour. Risk communication has several objectives. It has the role to prevent risks, to reduce them and to make communities aware of the risks in order to develop their capacities, enhance communication and resilience to respond to crisis events.

Investigation Techniques for the Seismic Response Assessment of Buildings Located in Historical Centers

ABSTRACT It is an acknowledged fact that historical centers, given its significance from the cultural and architectural viewpoint, bring further challenges in terms of maintenance planning, survey, and safety assessment. The preparation of an adequate investigation plan and the extent of data to be collected is highly reliant on many aspects, such as the category of the architectonic asset, the importance of the heritage site, or the resources available, for example. In what regards the seismic response assessment of urban cultural heritage assets located in historical centers, the amount and detail of data also depend on this article, scale of assessment, and current state of conservation and occupation. Within this framework, this article provides an overview of the state of the art of investigation techniques currently used in survey operations, which are currently available for improving the knowledge level of urban cultural heritage assets within historical centers, as a supporting tool for the seismic response assessment of such singular assets. Finally, acknowledging the lack of accuracy when evaluating the seismic response of an asset enclosed in aggregate as an isolated structure, this article also focuses on the identification of the main particularities inherent to buildings enclosed in aggregate.

The role of perception and communication in mitigating earthquake risk

Civic education and formation of public conscience constitutes one of the first and more important tools towards improving the awareness and perception of citizens to earthquake risk, taking a fundamental role on the construction of more resilient societies. However, since it requires the involvement of all citizens without exception, the creation and embedding of a risk culture represents a transversal challenge to our society. Being aware of this issue, this paper deals with earthquake risk perception and communication in Portugal, and discusses the results of a survey carried out resorting to a questionnaire specifically developed in the scope of the URBSIS research project. The questionnaire, which aimed at assessing the public knowledge and awareness on earthquake risk, had as target-public the residents of the Riverside neighbourhood of Faro, named Bairro Ribeirinho, and the local technical community related, directly or indirectly, to the construction and urban planning sectors.