Examination of 3D Finite Difference Analyses of Zonguldak-Kozlu CCR Dam Subjected Strong Ground Motions Considering Dam-Foundation-Reservoir Interaction

Abstract

Dams are one of the most important water structures built to meet the vital needs of people such as irrigation and energy. It is of great importance to examine the seismic safety of important water structures such as dams. In addition, it is vital to investigate the interaction behavior of dams due to the bodies of the dams, the reservoir water, and the foundation being in constant interaction. Therefore, in this study, the seismic behavior of clay core rockfill (CCR) dams is investigated by considering the dam-foundation-reservoir interaction. The Kozlu CCR dam, which was built in Turkey-Zonguldak, is chosen for seismic analyses. Three-dimensional (3D) modeling and analysis of the dam are performed utilizing the FLAC3D program. The foundation section is extended down to the height of the dam, and free-field and quiet non-reflecting boundary conditions are defined to the lateral boundaries of the foundation. Besides, the fix boundary condition is taken into account in the base section of the foundation. The Mohr-Coulomb material model is utilized for dam body material and foundation. Special interaction elements have been assigned between the discrete surfaces. These elements are affected to the 3D model of the dam in the x, y, and z directions. A total of 10 different earthquakes are used for earthquake analyses. Accelerations are defined in the program with the help of special fish functions and accelerations are applied to the base of the dam. As a result of the earthquake analyses, it is concluded that significant displacement and principal stresses occurred in the dam body for each earthquake. Moreover, as a result of this study, the dam-foundation-reservoir interaction problems of CCR dams are revealed by considering different ground motions.