Evaluation of Hydrodynamic Pressure Distribution in Reservoir of Concrete Gravity Dam under Vertical Vibration Using an Analytical Solution

Abstract

Fluid-structure interaction causes a hydrodynamic force, which can be exerted to the dam and affects its response. The effect of vertical excitation of ground motion on dynamic behavior of concrete gravity dam is the most important because of the interaction between foundation and reservoir. So, the foundation-reservoir interaction should be taken into account in designing concrete dams. In most studies, the effects of the vertical component of vibration have been ignored. While in vertical vibration, due to the interaction of the reservoir and the foundation, a significant hydrodynamic pressure is produced in the tank, which increases the dam response. In this study, the hydrodynamic pressure wave propagation in the reservoir of a concrete gravity dam caused by interaction with the foundation under vertical vibration is investigated using an analytical method. To achieve an analytical solution, the reservoir is assumed to be rectangular, and a harmonic load is vertically applied on the system from the foundation. Considering the acoustic nature of the reservoir fluid under harmonic vibration, a new method using the separation of variables method has been used for solution of hydrodynamic wave equation. The results show a significant effect of the vertical component of earthquake on the amount of induced pressure distributed in the reservoir, which has been omitted in most previous studies. Obtained results of the proposed model can be extended to more complicated models in terms of different loading and geometrical conditions.

Influences on the Seismic Response of a Gravity Dam with Different Foundation and Reservoir Modeling Assumptions

“…Chopra [5] revealed that using added mass to simulate hydrodynamic effects ignores the water compressibility, which would lead to unreliable decisions in the seismic analysis of concrete dams. Khiavi et al [28] investigated the hydrodynamic response of a concrete gravity dam and reservoir under vertical vibration using an analytical method. Amina et al [29] conducted a series of modal analyses of the Brezina concrete arch dam based on the Lagrangian and added mass approaches.…”

Numerical effect of seismic force on a medium arch dam

“…This old method was an easy one since the technology was not well developed in the past as now. This method considers the inertia force of the dam, and the hydrodynamic forces, which developed from water waves (Nath 1971;Melo & Sharma 2004;Pasbani Khiavi et al 2021). The weight of the theoretical sliding mass 'M' and the seismic coefficient 'k' are used to measure the magnitude of the static inertial load, which represents the seismic load 'F'.…”

“…Pasbani Khiavi et al (2021) examined the responses to achieve the optimal body stiffness using probabilistic and uncertainty methods after evaluating the effect of Young Modulus of both the body concrete and the foundation as strength parameters for concrete arch dams. The dam-reservoir-foundation system's finite element analysis was completed using ANSYS software, and the Monte Carlo method, a new method for parametric study and sensitivity analysis, was used for uncertainty analysis.…”

A Novel Calculation Method of Hydrodynamic Pressure Based on Polyhedron SBFEM and Its Application in Nonlinear Cross-Scale CFRD-Reservoir Systems

“…It is difficult to use conventional methods, which support only triangle and quadrilateral grids, to solve and compute the hydrodynamic pressure of a reservoir with polygonal grids under an earthquake. In the analysis of the seismic safety evaluation of dams, the hydrodynamic pressure is an important influencing factor that cannot be ignored [30][31][32][33]. Considering the important influence of hydrodynamic pressure on dam response, it is an urgent problem, which until now remains to be solved, for a cross-scale dynamic dam analysis system based on a polyhedron SBFEM.…”