Page - 1070 - in Book of Full Papers - Symposium Hydro Engineering

3.6. INITIAL HYDRAULIC MODEL RAMSELE: Similarly, a physical model was built for Ramsele (Billstein et al. 2016), with the main objective to attain optimal design of the prolongated spillway chute. All three spillway chutes were included in the model, since it was necessary to examine various configurations of gate openings, as well as operation of the left chute, see figure 11 below. It was also of some interest to determine the total discharge capacity of the dam facility. Figure 11: Hydraulic model of Ramsele dam, scale 1:50, with the proposed prolongated left chute (Vattenfall R&D, 2014) 3.6.1. Spillway Discharge Capacity The discharge capacity of all three spillways was determined by physical modeling, and was found to agree with the original design values. 3.6.2. Energy dissipation / prevention of rock erosion The planned design of the prolongated chute was included in the physical model upon which a number of tests were done, including measurements of velocity and wave activity along the slopes at the sides. During the testing phase, an alternative design was proposed: a shorter prolongation with a ski- jump at the end. The design change was chiefly motivated by cost reduction, as the construction length could be decreased by 30% to about 35 m. Spillway, three gates Bottom outlet Left chute 1070