This study investigates the seismic performance of a theoretical hospital building designed as a Fixed-Base (FB) structure according to TSC-2018 (Turkish Seismic Code) and evaluates its behavior under three scenarios: FixedBase (FB), Soil-Structure Interaction (SSI), and Base-Isolated (SSI+ISO). The study employs Nonlinear Time History Analysis (NLTHA) using scaled acceleration records, including one from the 2023 Maras, earthquake. Structural performance is assessed based on maximum roof displacements, interstory drift ratios (IDR), and isolator displacements. Results show that base isolation systems significantly reduce drift demands and roof displacements, keeping the structure within slight damage limits even under extreme seismic loads. In contrast, SSI effects amplify interstory drift demands, increasing the likelihood of exceeding moderate damage thresholds. The analysis highlights the Maras, Education and Research Hospital, which suffered severe damage and became non-operational during the 2023 Kahramanmaras earthquake. This outcome underscores the limitations of fixedbase designs in regions with soft soil conditions and the necessity of incorporating base isolation systems to improve seismic resilience. The findings emphasize the importance of mandatory adoption of base isolation systems in hospital designs, proper consideration of SSI effects, and the retrofitting of existing hospital buildings to meet modern seismic code requirements (TSC-2018) and prevent similar failures in future seismic events.
