plan and methods
The evaluation of seismic risk of built-up areas is associated to the level of local hazardousness, building vulnerability and level of exposure. Within this holistic approach that defines seismic risk, building vulnerability is from all three variables, the one that assumes greater importance not only because of its obvious physical consequences in the occurrence of a seismic event, but also because it is the potential aspect, for which the seismic engineering research can intervene, improve and even control seismic behaviour of existing buildings by reducing the level of vulnerability and consequently the level of physical damage, economical loss and life loss [5, 22].
Other seismic prone countries, have accumulated experiences with positive results on the economical, social and cultural level from investments made in this field. In the United States, in the 70´s, the government created the National Earthquake Hazards Reduction Program (NEHRP), financing research on seismology and earthquake engineering. Their national programs in risk reduction, civil protection and the educational promotion of earthquake safety are the practical outputs that have saved lives and minimised exposure in the recent events and are consequently updated and revised. Regarding Continental Portugal, historical earthquake reports, knowledge on seismic hazard, and a great number of masonry buildings without earthquake resistant design, indicate that part of the Portuguese population live under a considerable seismic risk. Among Portuguese regions, Algarve and Azores were severely affected by several historical earthquakes, such as the 1755 and 1998 respectively.
Despite all the excellent information and research material developed in our country, little has been done on a global national level to safeguard and retrofit old masonry buildings classified as heritage of national and international interest. Portugal (continental and islands) is located in a moderate to high prone seismic risk area, therefore the opportunity to take head and action on this topic of public interest, could surely motivate and lead to a necessary culture towards earthquake risk mitigation. Earthquake risk management is the major task within the complex net of interests of a urban system. Risk management as we foresee in our research project is an exercise of correlation of various impacts at different levels: economical, human, organisational, architectural and cultural. Our work proposal introduces a new perspective and motivates the safeguarding of the old masonry building stock, preserving the built heritage. It should be stressed that part of the old city centre of Coimbra is undergoing a process of UNESCO [23] classification for world heritage, as well as the traditional architecture (masonry buildings and dwellings) of the Azores islands. Therefore the investment in knowledge, by means of a scientific approach, with a assured practical and technical output is clearly perceived by the seven interdependent tasks planned (see attached file: Project Flow Diagram.pdf). The analysis of building performance in recent earthquakes, has allowed to identify the structural aspects that mainly influence their vulnerability, and consequently in the occurrence of damage mechanisms. Our approach to the vulnerability assessment and earthquake management is a innovative hybrid method in respect to the classification criteria exposed in the literature review [6]. The improved methodology is based on the treatment of the building information gathered from the field survey and introduces a more detailed analysis of the parameters evaluated and the introduction of new parameters that take into account the interaction amongst buildings (fact of buildings belonging to structural aggregates) and other overlooked building features already identified. However the vulnerability assessment can only make sense if vulnerability functions are developed and calibrated as proposed in task 4. Once developed it is assured the relation between the vulnerability with damage and loss estimation algorithms. The construction of seismic scenarios using a spatial analysis tool [24] can provide us with geo-referenced information, totally integrating the entire probabilistic algorithm in the definition of risk scenarios. The choice of the GIS tool (Geographic Information System) is essential, because it allows the analysis, facilitates management and representation of spatial information. In the future it is possible that all this information can be accessed through the internet, allowing the comparison between different methods. Within the work proposed in task 6, this research program intends the development of a mechanical approach for the vulnerability assessment of masonry buildings. A first analytical formulation will identify and discuss the interpretation of uncertainties that affect the capacity spectrum and the damage limit states. The capacity spectrum method on which the proposed model will be based represents a strong alternative to other vulnerability simplified methodologies when a good survey of the building stock is available. In this case parameters are derived from a statistical treatment of a database (task 1 and task 2).
In summary the main purpose of this project is to develop tools, to contribute for urban management and for the definition of future national guidelines for the evaluation and mitigation of seismic risk, taking into account the characteristics and the value of the built heritage of traditional masonry buildings. The results that can be expected from the URBSIS project are:
The institutions involved (University of Aveiro and the Technical University of Lisbon) have recently produced scientific publications together and grown closer. At the University of Aveiro, one PhD thesis and two Master thesis have developed work specifically for Coimbra [25] and Aveiro, and at the Technical University of Lisbon, researchers have over the past 10 years accumulated experience in the Azores islands. Therefore the proposal accounts with a solid scientific background needed to accomplish the tasks proposed. The research team has already done several studies on this issue and shows a huge motivation to continue the research started in this field.
The genesis of this research project anticipates what has been published in the Resolution of the Portuguese Parliament [1] and the tasks defined in the field of this research project are in accordance with the measures published and defended by this document.
project flow diagram
The evaluation of seismic risk of built-up areas is associated to the level of local hazardousness, building vulnerability and level of exposure. Within this holistic approach that defines seismic risk, building vulnerability is from all three variables, the one that assumes greater importance not only because of its obvious physical consequences in the occurrence of a seismic event, but also because it is the potential aspect, for which the seismic engineering research can intervene, improve and even control seismic behaviour of existing buildings by reducing the level of vulnerability and consequently the level of physical damage, economical loss and life loss [5, 22].
Other seismic prone countries, have accumulated experiences with positive results on the economical, social and cultural level from investments made in this field. In the United States, in the 70´s, the government created the National Earthquake Hazards Reduction Program (NEHRP), financing research on seismology and earthquake engineering. Their national programs in risk reduction, civil protection and the educational promotion of earthquake safety are the practical outputs that have saved lives and minimised exposure in the recent events and are consequently updated and revised. Regarding Continental Portugal, historical earthquake reports, knowledge on seismic hazard, and a great number of masonry buildings without earthquake resistant design, indicate that part of the Portuguese population live under a considerable seismic risk. Among Portuguese regions, Algarve and Azores were severely affected by several historical earthquakes, such as the 1755 and 1998 respectively.
Despite all the excellent information and research material developed in our country, little has been done on a global national level to safeguard and retrofit old masonry buildings classified as heritage of national and international interest. Portugal (continental and islands) is located in a moderate to high prone seismic risk area, therefore the opportunity to take head and action on this topic of public interest, could surely motivate and lead to a necessary culture towards earthquake risk mitigation. Earthquake risk management is the major task within the complex net of interests of a urban system. Risk management as we foresee in our research project is an exercise of correlation of various impacts at different levels: economical, human, organisational, architectural and cultural. Our work proposal introduces a new perspective and motivates the safeguarding of the old masonry building stock, preserving the built heritage. It should be stressed that part of the old city centre of Coimbra is undergoing a process of UNESCO [23] classification for world heritage, as well as the traditional architecture (masonry buildings and dwellings) of the Azores islands. Therefore the investment in knowledge, by means of a scientific approach, with a assured practical and technical output is clearly perceived by the seven interdependent tasks planned (see attached file: Project Flow Diagram.pdf). The analysis of building performance in recent earthquakes, has allowed to identify the structural aspects that mainly influence their vulnerability, and consequently in the occurrence of damage mechanisms. Our approach to the vulnerability assessment and earthquake management is a innovative hybrid method in respect to the classification criteria exposed in the literature review [6]. The improved methodology is based on the treatment of the building information gathered from the field survey and introduces a more detailed analysis of the parameters evaluated and the introduction of new parameters that take into account the interaction amongst buildings (fact of buildings belonging to structural aggregates) and other overlooked building features already identified. However the vulnerability assessment can only make sense if vulnerability functions are developed and calibrated as proposed in task 4. Once developed it is assured the relation between the vulnerability with damage and loss estimation algorithms. The construction of seismic scenarios using a spatial analysis tool [24] can provide us with geo-referenced information, totally integrating the entire probabilistic algorithm in the definition of risk scenarios. The choice of the GIS tool (Geographic Information System) is essential, because it allows the analysis, facilitates management and representation of spatial information. In the future it is possible that all this information can be accessed through the internet, allowing the comparison between different methods. Within the work proposed in task 6, this research program intends the development of a mechanical approach for the vulnerability assessment of masonry buildings. A first analytical formulation will identify and discuss the interpretation of uncertainties that affect the capacity spectrum and the damage limit states. The capacity spectrum method on which the proposed model will be based represents a strong alternative to other vulnerability simplified methodologies when a good survey of the building stock is available. In this case parameters are derived from a statistical treatment of a database (task 1 and task 2).
In summary the main purpose of this project is to develop tools, to contribute for urban management and for the definition of future national guidelines for the evaluation and mitigation of seismic risk, taking into account the characteristics and the value of the built heritage of traditional masonry buildings. The results that can be expected from the URBSIS project are:
- Characterisation of the masonry building stock of Portugal, representative of Mediterranean Europe;
- Creation and development of vulnerability assessment methodologies for facades and building aggregates;
- Creation of vulnerability functions and their calibration;
- Development of a GIS tool for seismic risk scenarios;
- Creation of post earthquake assessment survey forms;
- Information support for emergency management and planning;
- Workshop organisation and guideline manual.
The institutions involved (University of Aveiro and the Technical University of Lisbon) have recently produced scientific publications together and grown closer. At the University of Aveiro, one PhD thesis and two Master thesis have developed work specifically for Coimbra [25] and Aveiro, and at the Technical University of Lisbon, researchers have over the past 10 years accumulated experience in the Azores islands. Therefore the proposal accounts with a solid scientific background needed to accomplish the tasks proposed. The research team has already done several studies on this issue and shows a huge motivation to continue the research started in this field.
The genesis of this research project anticipates what has been published in the Resolution of the Portuguese Parliament [1] and the tasks defined in the field of this research project are in accordance with the measures published and defended by this document.
project flow diagram