Analysis of Seismic Behavior of an Earthen Dam

The current research focuses on the dynamic study of the 260.5 m high Tehri dam, which spans the Bhagirathi River in India’s Garhwal Himalayas. Since it was constructed in seismic zone-IV, there is a significant risk of an earthquake with a magnitude of 7–8.5 or more on the Richter scale in the area. Earthquakes with hypo-central distances of 50.6 km and 89.7 km from Tehri region occurred in the years 1991 (Uttarkashi earthquake) and 1999 (Chamoli earthquake), respectively, according to the data stored in Strong-Motion Virtual Data center (VDC). Hence, the repetition of such seismic activities in the Tehri region is highly probable. In this paper, numerical modeling is carried out using finite element analysis-based ABAQUS software to simulate a magnitude 7.8 earthquake in Nepal and calculated spectral accelerations. Response spectrum graphs are prepared using SEISMOMATCH, which are validated with IS: 1893:2016 (PART-1), and the spectral accelerations are scaled to 7.8 magnitude Nepal Earthquake in the Himalayan belt, with the help of which maximum acceleration is calculated. Finite element method and approximate methods are compared to obtain the crest acceleration in dam and give satisfactory results.