Project 2.5: Assessing Seismic Safety of Dams Under Near-Fault Seismic Wavefields and Methods to Shield Dams from Seismic Waves

Dams are critical infrastructure for water supply and energy generation, yet their seismic safety remains a pressing concern, particularly in India where many structures predate modern seismic codes. Past earthquakes such as Koyna (1967), Chi-Chi (1999), and Bhuj (2001) have demonstrated the vulnerability of dams and their foundations to seismic damage. Assessing dam safety under earthquake loading is a multiphysics challenge, requiring consideration of soil-structure and fluid-structure interactions, pore water effects, and local site conditions. Elevated pore pressures can reduce soil strength, while dynamic water response amplifies loads on dam structures. Furthermore, near-fault seismic wavefields introduce complex, non-uniform ground motions that differ significantly from far-field approximations, necessitating advanced rupture-to-site simulations. This research aims to evaluate the seismic safety of gravity dams in India under near-fault conditions by modeling dam-foundation-water interactions and incorporating site-specific geology, stratigraphy, and topography. Case studies of dams located close to major faults, including Koyna and Srisailam, will be undertaken to analyze amplification, damping, and failure modes such as sliding, overturning, and foundation instability. In addition, innovative methods to shield dams from seismic waves will be explored. These include engineered topographic modifications and seismic metamaterials, which use periodic inclusions to attenuate ground motion across frequency ranges.