Research into protection of rockfill dams from overtopping using rockfill downstream toes

The main cause of rockfill and embankment dam failures is overtopping due to insufficient outlet works. During the last 15 years, the Civil Engineering Department: Hydraulics and Energy of the Technical University of Madrid has been studying the overtopping failure process of rockfill dams. One of the aims of this research is to develop design criteria of cost-effective rockfill dam protections to avoid failure due to such overtopping. Among the different types of known protection, this analysis has focused on downstream rockfill toes. The objective of this study is to achieve stability of the downstream shell of rockfill dams to prevent mass slides. This article summarizes the results of the preliminary experimental and numerical tests developed during the year 2008. Preliminary conclusions show the feasibility of this protection to mitigate partially or totally the serious consequences of overtopping in rockfill dams.