Abstract: Oyuk dam is one of the only two hardfill dams with the height of more than 100m in the world. The obvious heterogeneity of hardfill material on microscopic level had been taken into consideration based on the macro-homogeneity assumption. The working behaviors of Oyuk dam under normal operation condition and earthquake condition were analyzed by using damage FEM. The failure modes and structural safety of dam under static and seismic conditions were explored in the presnce of water overload and seismic over load, and the results were compared with that obtained from elastic-plastic constitutive model. The results show that the whole profile of dam body is almost compressed under the conditions of normal operation and operation basis earthquake (OBE). The dam owns high strength and anti-sliding safety factors and is basically in an elastic working state. The failure mode of Oyuk dam is mostly integral sliding in static condition, but the dam is proved to possess high overload safety for waterload and strong earthquake-resistance. The dam’s failure process and failure modes analyzed by the damage constitutive model in consideration of material heterogeneity is more in conformity with the actual situation than that analyzed by elastic-plastic constitutive model.

Key words: Oyuk dam, hardfill dam, microscopic heterogeneity, failure mode, structural safety