Seismic Performance Assessment of Gravity Dams for Urban Flood Risk Mitigation Using the Scaled Boundary Finite Element Method (SBFEM)

Rapid urbanization and climate change have intensified urban flood risks, necessitat-ing resilient infrastructure to ensure water security and flood mitigation. Gravity dams are critical for regulating flood discharge, yet their seismic vulnerability poses signifi-cant challenges, particularly under compound hazards involving earthquakes and ele-vated reservoir levels. This study introduces a novel seismic analysis framework for gravity dams using the Scaled Boundary Finite Element Method (SBFEM), which effi-ciently models dam–water and dam–foundation interactions in infinite domains. A two-dimensional numerical model of a concrete gravity dam, subjected to realistic seismic loading, was developed and validated against analytical solutions and conven-tional Finite Element Method (FEM) results, achieving discrepancies as low as 0.95% for static displacements and 0.21% for natural frequencies. The SBFEM approach accu-rately captures hydrodynamic pressures and radiation damping, revealing peak pres-sures at the dam heel during resonance and demonstrating computational efficiency with significantly reduced nodal requirements compared to FEM. These findings en-hance the understanding of dam behavior under extreme loading, supporting cli-mate-adaptive design standards and integrated hydrological-structural modeling. By addressing the seismic safety of flood-control dams, this research contributes to urban flood risk mitigation and the development of resilient water management systems ca-pable of withstanding climatic and seismic extremes.