Hydrodynamic Pressures on Arch Dam during Earthquakes

A complete three-dimensional finite difference scheme has been developed and used to analyze the nonlinear hydrodynamic pressures on arch dam during earthquakes. Both free-surface waves and nonlinear convective acceleration are included in the analysis. Various dam shapes and reservoir banks were studied and the characteristic of nonlinear contribution due to curved geometry and free-surface waves are discussed. Numerical experiments have been made to determine the desirable mesh size arrangements and time increments. The effects of surface wave and convective acceleration on hydrodynamic pressure could augment the hydrodynamic pressure to 10% larger than that of a linear analysis. For an earthquake with large ground displacement, a large rise of the water surface could probably happen and be a severe threat to human safety in recreational areas and even cause overflow to affect the safe operation of the arch dam. An empirical formula is given to predict approximate hydrodynamic force.