Modal and Response Spectrum Analysis of Hoover Dam Using ANSYS

Hoover Dam plays an important role in regional irrigation, water supply, and energy production. In recent years, the continuous decline in the water level of Lake Mead has weakened the stabilizing effect of the reservoir, potentially affecting the seismic response of the dam. To investigate this issue, a two-dimensional nonlinear finite element model of Hoover Dam was developed using ANSYS (2025 R2 Student Version). Several quadrilateral-dominated mesh schemes were compared, and a grid with a global element size of 4 m and local refinement to 1 m near the curved dam surface was selected to balance accuracy and computational efficiency. The results show that displacement and stress responses are mainly concentrated about 100 m below the upstream crest and 50 m below the downstream crest. When reservoir effects are included, crest displacement decreases, while maximum stress below the upstream crest increases. The maximum elastic strain occurs on the downstream face approximately 100 m below the crest. Overall, stress and deformation levels remain within accepted design limits, indicating stable structural performance. The results highlight the importance of reservoir mass and suggest that more detailed hydrodynamic modeling is needed for comprehensive dam–reservoir seismic assessment.