# Risk and Resilience Assessment of Lisbon's School Buildings Based on Seismic Scenarios
## 2 State of the Art on Seismic Risk Assessment and Mitigation for School Buildings  
### Background Codes and Guidelines  
Risk-mitigation strategies designed by governmental agencies should be based on a rational understanding of the risk of large building groups--or portfolios--at a country level (or in a smaller region). In this context, various risk assessment methodologies and prioritization schemes for buildings based on their relative seismic vulnerability/risk are available in the scientific literature and/or international standards/guidelines. The procedure proposed in the guidelines by the Applied Technology Council [29] uses a strength-based approach to define an earthquake capacity ratio, comparing the actual strength of the building to the code requirement for new buildings. Adjustments are also adopted to consider in situ material properties and insufficient detailing (compared to modern design). Such a capacity-to-demand ratio is defined as the earthquake capacity ratio, and it is calculated as the minimum of the component-by-component strength ratios. The New Zealand Society for Earthquake Engineering (NZSEE) defines an evaluation procedure based on various levels with increasing detail of analysis, similar to the one proposed by [PERSON] et al. [30]. The initial evaluation procedure (IEP) in the NZSEE guidelines, published in 2017 [31], aims to provide a broad indication of the seismic rating of a building based on a sidewalk survey. The evaluation is expressed in terms of the ratio (%NBS) of the displacement capacity of the building for the life safety limit state over the minimum capacity required for a new building for the same limit state. A baseline %NBS is calculated using specifically tabulated coefficients relating to year of design, strengthening interventions, importance of the structure, assumed ductility capacity, site hazard, presence of near-fault effects, soil type, etc. It is assumed that the capacity of the building cannot be lower than the minimum specified by the code valid for the year of design, if any. Furthermore, the procedure introduced by the Federal Emergency Management Agency [32] is based on a rapid visual screening of buildings and a two-level approach for a fast assignment of a seismic vulnerability index (which requires no mechanical-based calculation from the user). FEMA P-155 describes the rationale behind the scoring system, which is directly connected to the probability of collapse of archetype building categories. Such a method is based on the HAZUS framework (and typological force-displacement curves) to define the building categories and to derive a seismic-only assessment. Finally, Part 3 of Eurocode 8 (EN 1998-3) [33] consists in the current European basis for the seismic assessment of existing buildings. Although it proposes a series of recommendations for the assessment of building structures, a practical framework that integrates the analysis methods that are referred to in this document is yet to be developed. Referring to the education sector, a consistent effort was put forward by the World Bank in addressing these aspects with the implementation of the Global Program for Safer Schools (GPSS) [34]. Launched in 2014, the GPSS contributes to the Comprehensive School Safety Framework [5; 35] by financing and advising governments to implement safer school programs worldwide. As outlined in the Sendai Framework [36], \"while the drivers of disaster risk may be local, national, regional or global in scope, disaster risks have local and specific characteristics that must be understood for the determination of measures to reduce disaster risk\" [sic]. This is particularly valid in countries where risk data scarcity remains a major issue [37], and where there is a tendency to perform risk assessments with models from other regional contexts. In 1997, Alaska's Department of Education, among others, produced surveying forms to assess the structural conditions of buildings and the associated seismic vulnerabilities,with a focus on school buildings.