Response of Concrete Dams on Rigid and Soil Foundations Under Earthquake Loading

Abstract

Dynamic response of dams under earthquake loading depends on their foundation stiffness. Additional hydrodynamic pressures are generated not only by the ground motions but also due to the dynamic response of the dam to the ground motions. The magnitude and distribution of hydrodynamic pressures vary and these effect the deformation of dam which in turn influences the pressure. This paper aims at investigating the effect of dam–foundation interaction on the dynamic response and consequent development of hydrodynamic pressure on dam face using dynamic centrifuge modelling technique. From a series of centrifuge tests it was found that the inclusion of a flexible foundation significantly reduces the dynamic response of the dam. Significant correlation was also observed between the dynamic response of dams and the hydrodynamic pressures developed on their faces. Comparisons with theoretical hydrodynamic pressures show that Westergaard's equation gives a conservative estimation of hydrodynamic pressures during most nonresonant vibrations. Comparison with Chopra's method revealed that it severely underpredicts hydrodynamic pressures for low reservoir depths. However, it yields a reasonably good approximation of the hydrodynamic pressures for higher depth of reservoirs during nonresonant vibration.

Experimental Investigation of Seismic-Induced Hydrodynamic Pressures on a Vertical Wall under Conditions of Wave Resonance

“…Chen and Malenica [13] examined the distributions of hydrodynamic pressure on the surface of a ship hull for a large range of encounter frequencies. Saleh and Madabhushi [14,15] investigated the effect of dam-foundation interaction on the hydrodynamic pressure response on a dam face under different seismic excitations using the dynamic centrifuge modeling technique. This work proposed an experimental method for examining hydrodynamic pressure.…”

Experimental study on the applicability of Westergaard’s formula for calculating earthquake-induced hydrodynamic pressure in small lake

“…Wang et al [14] modified Westergaard's equation considering the influences of the dam height, elasticity, and reservoir bottom condition. Saleh and Madabhushi [15] investigated the effect of dam-foundation interaction on the hydrodynamic pressure response on the dam face under different earthquake waves using the dynamic centrifuge modeling technique. The results generated by these works were more or less equivalent to the results of Westergaard, and thus, the approximate formula has been widely used to calculate the hydrodynamic pressure loads.…”

Analytical estimation of natural frequency in earth dams with respecting to the foundation effects

“…Soil-structure interaction in concrete dams has been considered importantly by the researchers (e.g. Saleh and Madabhushi [12]). Based on their results, dam flexibility caused significant decrease of dynamic responses.…”