Structural Performance of Indonesian School Building: A Nonlinear Static Analysis for Earthquake and Tsunami Loads

Abstract Indonesia, situated on the Pacific Ring of Fire, is highly vulnerable to earthquakes and tsunamis, which have caused significant damage to school infrastructure. Despite national guidelines on constructing earthquake- and tsunami-resistant buildings, a critical gap remains in assessing the structural resilience of schools under multi-hazard scenarios. This study evaluates the structural capacity of typical two-storey reinforced concrete school buildings, focusing on bare frame and infilled wall structures, using pushover and Variable Depth Pushover (VDPO) analyses. Finite element models were developed in OpenSees, applying seismic and tsunami loads to derive capacity curves. The results reveal that while infilled wall structures exhibit higher initial stiffness and strength, they are prone to brittle failure once the infills degrade. In contrast, bare frame structures demonstrate greater ductility, sustaining larger displacements without abrupt failure. The VDPO analysis shows that the bare frame structure maintains stability under increasing hydrodynamic forces, while the infilled wall structure experiences rapid strength degradation due to the collapse of infills.