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

Abstract

Dams are one of the most important water structures built to meet people’s vital needs such as irrigation and energy. It is important 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, this study investigates the seismic behavior of clay core rockfill (CCR) dams by considering the damfoundation-reservoir interaction. The Kozlu CCR dam 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 dam’s height, and free-field and quiet non-reflecting boundary conditions are defined to the lateral boundaries of the foundation. Besides, the fix boundary condition is considered the foundation’s base section. 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 by the 3D model of the dam in the x, y, and z directions. A total of 12 different earthquakes (magnitudes of earthquakes are between 5.9 and 7.6) are used for earthquake analyses. X, Y, and Z directions of ground motion accelerations are defined in the program, 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, it is inferred that the seismic principal stress values occurring in the dam body with interaction elements are smaller than the values observed in the dam body without interaction elements.