SEISMIC ASSESSMENT OF SCHOOL BUILDINGS IN ITALY: RETROFIT AND RISK CLASSIFICATION

The potentially high vulnerability and poor performance of existing school buildings in Italy, reported after past seismic events, has raised awareness of the need to improve their seismic performance. In this context, a research project dealing with assessing the seismic risk of school buildings was conducted on representative typologies of the school building population in Italy. This paper explores some retrofit strategies for three specific school buildings representing the most common typologies of the Italian school building stock. A performance assessment was carried out using detailed numerical models developed to recreate the main structural deficiencies documented in similar buildings. Based on the performance assessment, retrofit schemes were proposed to address the main structural deficiencies and to meet code requirements for the different limit states. These requirements are set to limit the damage to non-structural elements and prevent non-ductile failure mechanisms in the structural systems, following a typical code and practitioner-oriented process. The retrofit alternatives were then evaluated through increasing shaking intensities to quantify risk-based decision variables such as expected annual loss and collapse safety. The results indicate the efficiency of the retrofit options utilized in reducing both the economic losses and collapse vulnerability of the buildings. Finally, the seismic risk classification guidelines, implemented recently in Italy, were applied at a national scale to estimate the seismic risk on existing school buildings in the Italian peninsula and the risk reduction achieved by each retrofit alternative. Consequently, budget programs can be derived based on national risk maps, prioritizing the investment of seismic retrofit interventions in regions of vulnerable school buildings.