SEISMIC PERFORMANCE OF A BITUMINOUS-FACED ROCKFILL DAM

The paper presents the assessment of the seismic performance of Menta dam, a 90m-tall rockfill embankment located in Calabria region, Southern Italy. A bituminous concrete face on the upstream side guarantees the dam impoundment. The dam was designed in the ‘70s and it is located in a narrow canyon which strongly affects the morphology of the foundation - embankment contact. In the framework of current practice in Earthquake Engineering, a particular consideration has been devoted to the definition of specific Limit States for the case at hand, looking at the embankment performance, hydraulic safety and post-seismic behaviour, also encompassing the recent Italian Technical Guidelines suggestions. Dynamic analyses have been conducted by using computational methods characterized by different level of complexity. Simplified methods, routinely used in common practice for stability problems and displacement analyses, have been firstly implemented, while advanced numerical analyses have allowed to assess the integrity of the bituminous facing lying on the upstream side of the dam. In the framework of simplified analyses, a methodology providing a probabilistic assessment, based upon direct displacement-based approach (DDB), was applied for the first time to dam in order to evaluate the global seismic vulnerability.