Identification of seismically vulnerable typologies of schools in Lisbon, Portugal

Details

Supervisors

Saraiva Esteves Pacheco De Almeida, João ; Costa, Alexandre

Faculty

Faculté d'architecture, d'ingénierie architecturale, d'urbanisme

Degree label

Master [120] : ingénieur civil architecte, à finalité spécialisée

Abstract

enGiven the seismic risk to which the city of Lisbon is exposed, the municipal authorities are seeking to improve the city's seismic resilience and thereby limit the impact of a disaster. The many actions to be taken are governed by the ReSist program. Faced with the magnitude of the task, the team aims to systematically prioritize its actions. These begin with understanding the overall condition of the building stock, in order to identify the most vulnerable buildings to be strengthened first, and to pinpoint the most robust ones that could be relied upon as part of an emergency plan following an earthquake (contingency plan). Many methods propose to analyze buildings on a large scale. Unfortunately, these methods are dependent on the context (type of earthquake, environment, building stock) in which they were developed. It is therefore necessary to adapt the method to the context of the studied region—in this case, Lisbon. The school building stock for which the general condition is being assessed includes 137 schools. Among them, 108 were built before the 1983 seismic design code, of which 58 were not structurally renovated before the year 2000—at which point renovations were also required to comply with seismic standards. These 58 schools to be examined were classified into 7 typologies based on their floor plans. First, the recommendations of Eurocode 8 published in 2004, and the seismic design guidelines theorized by Bachman in 2002, served as a basis for identifying the main strengths and weaknesses of these typologies. Then, the Rapid Visual Screening method published in FEMA-154 was used and adapted to the context of Lisbon’s schools. Finally, an analysis of the resistance of concrete load-bearing elements was carried out to address the lack of knowledge regarding their seismic load-bearing capacity. These assessments made it possible to obtain a global and informed judgment on the resilience of the school stock. One typology of schools built with a common plan between 1940 and 1960, and another typology from the 1970s, were found to be at risk in all three analyses. These two groups should become a priority for the municipal authorities to limit severe damage in the event of an earthquake. Conversely, one typology, present throughout Portugal since the 1980s, appears to be resistant. In the event of a disaster, these structures could be used as key aid centers.