Akademik Veri Yönetim Sistemi
Soil Dynamics and Earthquake Engineering, cilt.203, 2026 (SCI-Expanded, Scopus)
This study investigates the seismic fragility of typical 100 m3 reinforced concrete elevated water tanks (EWTs) widely constructed across Türkiye, many of which remain in service or stand abandoned. A nonlinear modeling framework is employed that incorporates confined material behavior, fluid–structure interaction (FSI), and soil–structure interaction (SSI). The tanks are analyzed under varying conditions, including two concrete strengths (C10-S220 and C20-S420), different reservoir fill levels (empty, half-fill, and full), and multiple soil classes (fixed base, C, D, and D1). A total of 24 three-dimensional finite element models were developed and subjected to nonlinear time-history analyses using 30 ground motion records scaled through the multiple stripe analysis (MSA) method, with spectral acceleration at T = 1.0 s (Sa1) as the intensity measure (IM). Fragility curves were derived using both element-based collapse criteria (single- and double-hinge mechanisms) and drift-based deformation thresholds. Results reveal that tank reservoir level, material strength, and soil condition significantly influence fragility. Full tanks demonstrate lower seismic vulnerability due to increased damping and mass participation, while SSI effects generally reduce seismic demand by elongating structural periods. Higher strength significantly improves seismic performance, particularly under empty or flexible soil conditions. These findings emphasize the need for integrated modeling of fluid-structure-soil interaction (FSSI) phenomena in the seismic evaluation of EWTs, especially for aging or structurally uncertain systems.