Date of Award
Civil and Environmental Engineering
McCorqoudale, J. A.,
CC BY-NC-ND 4.0
In dams with low tailwater levels, the hydraulic jump may not occur on the protected apron. This could result in a severe local scour on the downstream river bed which could endanger the safety of the dam. A traditional solution is to place crushed rock in the scour hole to prevent further scour; however, this method is not a permanent solution. The focus of this research is to investigate the effect, on the scour profile, of installing a secondary stilling basin downstream of the primary basin. This results in a dual stilling basin. The primary stilling basin is the original inadequate basin while the secondary stilling basin provides for the additional energy dissipation required to prevent excessive scouring in the river bed. In this research, the physical model of the Shand Dam was used as a case study. A 1:49 scale model of the Shand Dam was constructed in a 4.9 m long by 3.0 m wide by 0.8 m deep basin in the Hydraulic Engineering Laboratory (B03, Essex Hall) at the University of Windsor. Experimental work was carried out for various flows and end sill configurations in the secondary stilling basin. It was observed that within a few minutes a scour hole formed close to the structure; this is referred to as the short-term scour. A long-term scour formed farther from structure and increased by time. All the scour tests were conducted for half an hour to study short-term and long-term scour. Scour depths were measured at 56 points. From the scour profiles the best end sill slope to get minimum scour far from the structure was determined. Velocities were measured at selected locations at 0.2, 0.5 and 0.8 of the depth within the secondary stilling basin and above the end sill. Pressure values at different points on the secondary stilling basin were recorded with a data acquisition system. Spatial correlations in both longitudinal and lateral directions were determined in order to establish dynamic loading on the floor of the secondary basin. Source: Masters Abstracts International, Volume: 37-01, page: 0316. Adviser: J. A. McCorqoudale. Thesis (M.A.Sc.)--University of Windsor (Canada), 1997.
Sowlati Hashjani, Taban., "Hydraulic study of secondary stilling basins." (1997). Electronic Theses and Dissertations. 2335.