Dynamic analysis of concrete gravity dams using the evlerian and the lagrangion approaches

SUMMARY DYNAMIC ANALYSIS OF CONCRETE GRAVITY DAMS USING THE EULERIAN AND THE LAGRANGIAN APPROACHES In this thesis, it is purposed to perform the dynamic analysis of concrete gravity dams, considering dam-reservoir and dam-reservoir-foundation interactions, using the Eulerian and Lagrangian approaches. Therefore, the two and three dimensional fluid elements based on the Lagrangian formulation are firstly improved and programmed, and incorporated into a general- purpose structural analysis program SAP-IV. The accuracy of these elements is tested on the various problems whose analytical solutions are known. The static and modal analyses of the dam-reservoir system are performed using the two dimensional Lagrangian fluid elements. The effects of the variation of fluid compressibility on the modal distribution are also studied. The earthquake responses of the dam-reservoir and dam-reservoir-foundation systems are computed by the mode superposition method using the same fluid elements. The effects of foundation and reservoir on the response of the dam are studied. In addition, the Eulerian solutions, based on incompressible fluid assumption for dam- reservoir and dam-reservoir-foundation systems as well as compressible fluid assumption for dam-reservoir system, are obtained. These results are compared with those of the Lagrangian solutions. The three dimensional Lagrangian fluid elements are used only in the static and the earthquake analyses of the dam-reservoir system. The comparison between the earthquake analysis obtained by using both three and two dimensional fluid elements are performed. In both solution, Wilson- 6 step by step integration technique is employed. Key Words : Dynamic Analysis, Concrete Gravity Dam, Fluid-Structure Interaction, Eulerian Formulation, Lagrangian Formulation, Finite Element, Reduced Integration, Modal Analysis, Dam-Reservoir, Dam-Reservoir-Foundation. vn