Seismic response of a zoned earth dam (case study)

The Conza Dam is a rare case in literature of a zoned earth dam that during the construction stage (started in the 1979 and finished in 1988) was subjected to a very strong earthquake in almost near-source condition: the Irpinia earthquake (main shock on November 23, 1980; Richter magnitude of 6.9 and duration up to 80s). Settlements, pore water pressures and accelerations measured during different stages of the dam lifetime have been collected and interpreted. The effects of the 1980 earthquake on measured settlements of the dam embankment have been elucidated. By using a coupled dynamic approach based on the u-p formulation of the Biot consolidation theory, solved numerically with the finite element method, a numerical study has been performed in order to: (i) reproduce the observed permanent settlements of the dam embankment due to the 1980 Irpinia earthquake and (ii) predict the dam response to different seismic scenarios.