SEISMIC ANALYSIS OF THE HIGH ARCH CONCRETE DAM OF THE WATER POWER PLANT "PIVA"

This paper analyses the seismic strength of the high arch concrete dam of the Hydro-power plant "Piva" on the river Piva in Montenegro, which was built in the seismic active area almost forty years ago. This is the double curve concrete arch dam, 220 m high and it belongs to the group of very high dams, among the highest 25 in the world. Linear and nonlinear analysis was performed. These analyses are very complex because they should include simultaneous interaction of system dam-foundation-reservoir. Calculation model was prepared using 3D finite elements for linear and nonlinear seismic analysis. Normal stresses and displacements which are obtained by the linear and non-linear analysis are different by the values and distribution along the dam body. Stresses obtained by the non-linear analysis are significantly less than the stresses obtained by the linear analysis, but when the displacement is about there is inverse case. Linear analysis gives the satisfying results for lower levels of the dam stress. When the tension strength is exceeded in the joints among the blocks, the dam goes into non-linear state of behaviour and in that case non-linear analysis should be used.