Dynamic numerical analysis of the Mazar concrete faced rockfill dam in Ecuador – south america

Abstract

The catastrophic effects of earthquakes that frequently hit the West coast of South America has motivated this research. The country of Ecuador, situated on the subduction border of the South American and Nazca tectonic plates, has a high seismic exposure. Since the Mw = 7.8 earthquake that occurred on April 16th, 2016, the assessment of stability conditions of dams has become a high priority for the Ecuadorian government. The concrete faced rockfill dam (CFRD) of Mazar, an essential structure for the country, is classified as a large dam by the International Commission on Large Dams (ICOLD). In this research, the numerical seismic analysis of Mazar dam was carried out, including the generation of artificial earthquakes based on acceleration spectra established by Ecuadorian standards. Other aspects related to the dam behavior were also investigated, such as the static and pseudo static stability conditions and the maximum permanent displacements determined by simplified methods. An important conclusion from the 2D numerical analysis is the influence of topographic amplification, which is not taken into account when simplified methods based on 1D wave propagation are used.