SEISMIC AND TSUNAMI VULNERABILITY ASSESSMENT OF THE SHELTER SCHOOL BUILDING IN Padang City, INDONESIA

Abstract

West Sumatra Province is one of the most earthquake and tsunami-prone areas in Indonesia. Currently, tsunamis pose a serious threat to coastal areas in Padang City, as they can damage public buildings, including schools. Consequently, it is essential to assess the vulnerability of school buildings in coastal areas of West Sumatra. One of the school buildings that can function as a shelter in the city coastline area of Padang is SDN 23 Padang. In this study, vulnerability analysis is conducted using the development of a fragility curve. The seismic fragility curve was developed by analyzing the maximum structural displacement under various earthquake accelerations, obtained through dynamic response simulations and non-linear time history analysis scaled with the Incremental Dynamic Analysis (IDA) approach. The limit states were defined according to ATC-40 criteria and further classified using the HAZUS framework. For tsunami hazards, the fragility curve was derived from the peak displacement responses corresponding to different inundation depths. The seismic vulnerability assessment indicates a progressive probability distribution at a 0.6 g peak ground acceleration, where the likelihood of slight and moderate damage of the building reaches 100%, while extensive damage is approximately 74%, and the probability of collapse remains negligible. In contrast, the tsunami vulnerability assessment indicates that at an inundation height of 5 m, the likelihood of slight and moderate damage to the building is certain, the probability of extensive damage is 96%, and complete structural failure has a probability of approximately 10%.