Frequency response analysis of a generic dam-fluid-foundation model​

TitleFrequency Response Analysis of a Generic Dam-Fluid-Foundation Model
Author(s)Dr Pranesh Chatterjee, MASCE
PublishedJune 2013
KeywordsFluid-Dam-Foundation Interaction, Frequency Response Analysis, Bottom Absorption, Damping, Sommerfeld Radiation, Flexible Foundation


The objective of this paper is to perform frequency response analysis of a generic dam resting on a foundation. The foundation is considered to be both rigid and flexible. The analysis is done for both dry dam and full reservoir conditions. A set of four distinct cases has been studied which are respectively as follows: 1) dry dam on rigid foundation, 2) dry dam on flexible foundation, 3) full reservoir on rigid foundation and 4) full reservoir on flexible foundation. The dam is assumed to be made up of concrete material. The fluid, when considered, is meshed with fluid elements and fluid-dam interaction is considered. The foundation flexibility is represented in the DIANA model by introducing interface elements with suitable values of stiffness. The interface elements are also assigned damping properties to represent the effect of the far-field. The bed of the fluid domain is assumed to be rigid and hence fully reflective. A preliminary eigenvalue analysis is done to determine the eigen modes of the system considered and subsequently a direct frequency response analysis is performed for all cases. The DIANA results are compared with the results for a similar model studied by Fenves and Chopra (1984). The results are shown in terms of accelerations in frequency domain. The DIANA results seem to be in good agreement with the results reported by Fenves and Chopra (1984).