Damage Assessment and Seismic Modeling of Dams in Connection with the 2006 Hawaii Earthquakes

Two large earthquakes that rattled the Hawaiian chain in October of 2006 were strong enough to cause minor to moderate damage to four nearby dams, including longitudinal and transverse cracks in the embankment fills, incipient slope instability, and possibly delayed internal erosion and piping that triggered emergency water releases from two of the reservoirs. Recent seismic studies by the first author indicate that many dams in Hawaii are potentially susceptible to severe damage from earthquake shaking due to an active seismic environment in some parts of the State. Adding to a general level of uncertainty are outdated construction methods used for dams as old as 120 years, relatively unknown dynamic characteristics of local volcanic soils, and a lack of sufficient understanding of strong motion propagation throughout the Islands.