Salamonde dam complementary spillway. Design, hydraulic model and ongoing works

Abstract

In order to meet the updated requirements of the Portuguese Dam Safety Legislation, Salamonde dam (double curvature arch dam, dated 1955) hydraulicoperational safety assessment has been developed by EDP, including the review of the design flood and the evaluation of safety devices capacity. Thereafter some corrective measures were implemented, including the construction of a new complementary spillway. The paper summarizes the main features of the new spillway design, developed by AQUALOGUS. The selected solution is a gate-controlled ogee crest, followed by a 120 m long curved tunnel scoped in the slope of the right bank designed for a discharge of 1233 m3/s. The hydraulic performance of the designed structure was analysed by a study developed on a hydraulic physical model, built at LNEC on an approximate scale of 1/50. Part of the results and conclusions that allowed improving the design structure shapes is described. Some aspects of interesting and nowadays challenging ongoing works of this new spillway are presented.