Earthquake And Tsunami Risk Prioritisation of Indonesian Schools Through Rapid Visual Survey

Located on the Ring of Fire, Indonesia is a highly earthquake-and tsunami-prone country, continuously experiencing disastrous events (e.g., the recent 2018 Sulawesi earthquake and tsunami). Educational facilities demand special attention in terms of priority for assessment and retrofit, given the strong bond between access to education and development and the higher vulnerability of school children to natural hazards. This paper first presents the results of a campaign of rapid visual surveying on 88 reinforced concrete (RC) school buildings in Banda Aceh, Indonesia. To this aim, a form has been developed by the authors allowing to collect relevant structural engineering information in a systematic and effective way. The collected data is used to define an empirical earthquake-tsunami relative risk prioritisation scheme for the surveyed buildings. This is based on a seismic riskindex, recently proposed by the authors, and the revised Papathoma Tsunami Vulnerability Assessment (PTVA) index for tsunami. Consistently with the prominent trends in the geometric/mechanical data, the results show that the seismic vulnerability is similar for all the considered buildings, and the prioritisation ranking is strongly governed by the distance of the buildings from the coast, which is a proxy for the tsunami risk. The analysis of the geometrical and mechanical data further allows to identify clear trends in the construction practice, and to define an index buildingrepresenting the whole portfolio. Seismic fragility and vulnerability functions of the index building can bederived through a refined nonlinear numerical model of the archetype school building