Materially linear and nonlinear dynamic analyses of arch dam-water-foundation systems by Lagrangian approach

SUMMARY Materially Linear and Nonlinear Dynamic Analyses of Arch Dam- Water-Foundation Systems by Lagrangian Approach In this thesis, materially linear and nonlinear dynamic responses of arch dam-water- foundation systems are investigated by Lagrangian approach. Curve description and Drucker-Prager models are used to represent the nonlinear behavior of the dam concrete. Three-dimensional Drucker-Prager model and three-dimensional 8-noded Langrangian fluid finite element are incorporated into NONSAP, a general-purpose structural analysis program, by coding in the language FORTRAN 77. The modified program was employed in the response calculations. Water and foundation rock are assumed to be linear elastic. As a numerical example, Type-5 arch dam is selected as was suggested in the symposium on Arch Dams, London, 1968. This thesis consists of five chapters. In the first chapter, a literature survey associated with fluid-structure interaction and the nonlinear behavior of concrete dams is given in detail. This chapter also contains formulations associated with three-dimensional material models, Lagrangian fluid elements and solution techniques of linear and nonlinear equations used in the thesis. In the second chapter, the general performance of three- dimensional Lagrangian fluid finite elements in fluid-structure coupling is evaluated and developed Drucker-Prager model is tested. In addition, three-dimensional finite element models of dam, dam-water interaction, dam-foundation rock interaction and dam-water- foundation rock interaction systems prepared for the selected arch dam are introduced. Third chapter contains the findings obtained from the linear and nonlinear analyses. The conclusions and recommendations deduced from the analyses are given in chapter four. In this chapter, it is emphasized that water in the reservoir and foundation rock should be considered in the dynamic analyses of the slender structures such as arch dams. In addition, it is pointed out that Drucker-Prager model can be used to represent the nonlinear behavior of the concrete material. Finally, the references are presented in the fifth chapter. Keywords: Linear Dynamic Analysis, Nonlinear Dynamic Analysis, Curve Description Model, Drucker-Prager Model, Dam- Water-Foundation Interaction, Reduced Integration, Runge-Kutta Method, Hydrodynamic Effect, Finite Element Method IX