Iterative analysis of concrete gravity dam-nonlinear foundation interaction

Abstract

This paper deals with finite element analysis of the soil–structure systems considering the coupled effect of elastic structure and materially nonlinear soil. The equations of motion of both soil and structure have been expressed in terms of displacement variable. The structure and the soil domain are treated as two separate systems. The solution of the coupled system is accomplished by solving the two systems separately and then considering the interaction effects at the soil–structure interface enforced by a developed iterative scheme. Emphasis has been laid on the study of material nonlinearity of the foundation material in the interaction analysis. The results show the pronounced effects of displacements and stresses for the structure when the foundation is assumed to be composed of nonlinear materials. A widely popular model called Duncan-Chang model has been used for representing nonlinear material behavior of soil/rock. In order to represent the semi-infinite nature of the foundation domain, the Lysmer-Kuhlemeyer boundary condition consisting of viscous dashpots have been used. Studies show the accuracy
of the proposed algorithm, while comparing with the results reported in the literature.

Keywords: Concrete gravity dam; dam-foundation interaction; iterative algorithm; Duncan-Chang model; viscous dashpots.