Seismic Analysis of Concrete Gravity Dams on Non-Uniform Foundations

One of the simplifying assumptions made for dynamic analysis of concrete gravity dams is the uniformity of the foundation with respect to physical parameters such as elasticity modulus and damping. In practice, however, different parts of a dam foundation often exhibit varied geological conditions. Geological and rock mechanics reports typically describe dam foundations as non-uniform. Under such conditions, the parameters of the weakest area are often used as representative values for dynamic analysis, or a weighted average of parameters is defined for model input. This research investigates the seismic behavior of a 110-meter-high concrete gravity dam under the influence of a non-uniform foundation. Using the Abaqus software, a finite element model of the dam, lake, and foundation system is developed. The model calculates the dam's response by considering the interaction between the dam, foundation, and lake during an earthquake with a peak acceleration of 0.8g. Comparisons of stress and displacement at the dam's crest reveal that non-uniformity assumptions significantly affect the stress exerted on the dam. The results also demonstrate that stress distribution patterns within the dam body differ markedly from those in a uniform state.