EARTHQUAKE RESISTANT DESIGN OF EARTH AND ROCK-FILL DAMS

Abstract

Given the possibly disastrous effects of a dam failure during an earthquake, the seismic vulnerability of embankment dams has been a major worry. The present research delves into the concepts and techniques utilized in the seismic assessment and planning of embankment dams, stressing the importance of a thorough strategy that incorporates geotechnical, structural, and dynamic factors. An effective embankment dam design should be risk-free and cost-effective. The planned construction must be long-lasting and require no upkeep. In addition, the building ought to fulfill the purpose for which it was intended. When compared to gravity dams, embankment dams offer numerous benefits. The embankment dams ought to be built to resist earthquake-induced ground trembling. Case studies of current embankment dams that have experienced seismic activity are looked at in order to confirm the efficacy of different design strategies and pinpoint lessons discovered. This study adds to the continuing attempts to create standards and guidelines for earthquake-resistant design in the context of embankment dams by combining the results from theoretical analysis with real-world applications. Damages due to earthquakes in the Himalayan region has been observed. The state of Uttarakhand is situated in the Himalayan foothills, and it is under high seismic zones (IV and V) as per IS 1893 (2016). Tehri Dam is a unique example of Earth and Rockfill dam, located in Uttarakhand. It is also the tallest dam in India, which experienced many earthquakes e.g., 1991 Uttarkashi earthquake and 1999 Chamoli earthquake. In the present study, two-dimensional finite element analysis (2D-FEA) is carried out to investigate the behavior of Tehri dam under the 1999 Chamoli earthquake with Peak Ground Acceleration (PGA) 0.375 g. The viscous boundary is applied at the side of the FEA model and the bottom of the model is fully fixed. The 1999 Chamoli earthquake was applied in the horizontal direction. Linear Elastic Model as well as non-linearity of the dam using, Mohr-Coulomb (M-C) model in PLAXIS 2D.