Comparative Analysis of Earthquake-Induced Hydrodynamic Pressures in Dam–Reservoir Systems Using CFD and Analytical Methods

Abstract

Hydrodynamic pressures induced by earthquake excitation constitute a critical load component in the seismic safety assessment of dam–reservoir systems. In this study, earthquake-induced dynamic pressures acting on a rigid dam face were investigated numerically and compared with classical analytical approaches. A three-dimensional reservoir model with dimensions of 3 m × 3 m × 4 m was established in ANSYS Fluent, and an initial water depth of 2.5 m was defined. The fluid domain was discretized using 5 cm cubic cells, resulting in 288000 elements. A two-phase flow model was employed, and the free-surface motion was tracked using the Volume of Fluid (VOF) method under transient conditions. As seismic input, the East–West component of the February 6 Kahramanmaraş earthquake record obtained from the Göksun station (No: 4612) was used. The strong-motion interval of the record was applied in the numerical analyses. The pressure distributions obtained from the computational fluid dynamics (CFD) model were compared with the results of the Westergaard, Von Kármán, and Zangar methods. The numerical results indicated that the location and magnitude of peak hydrodynamic pressures varied with time, whereas the classical analytical methods generally predicted the maximum pressure at the dam base. The findings show that classical methods may provide practical and conservative estimates for overall loading, while CFD analysis offers a more detailed representation of time-dependent local pressure concentrations on the dam surface.