Numerical Assessment of a Concrete Gravity Dam under Multi-Scenario Loading: Case Study of Koyna Dam

Concrete gravity dams are among the most important elements of water infrastructure, ensuring reliable water supply, effective flood control, and renewable energy generation. Their safety, however, depends on understanding how they respond to both everyday operations and extreme events. This study focuses on the Koyna Dam, using a two-dimensional finite element model in ANSYS to explore its behaviour under different loading scenarios. The model includes dam–reservoir–foundation interaction and pays particular attention to seismic forces and hydrodynamic effects, which are often the most critical for long-term stability. The loading conditions were defined using guidelines from the United States Army Corps of Engineers (USACE), providing a standardized and realistic basis for evaluation. To refine accuracy, a mesh sensitivity analysis was performed to identify the most efficient element size. The results highlight clear patterns of displacement and stress within the dam, offering practical insights into how different loads influence its performance and resilience.