Canal Wave Oscillation Phenomena Due to Column Vortex Shedding

Adam M. Howes, Utah State University

This work made publicly available electronically on June 10, 2011.


The GARVEE Transportation Program started by the Idaho Transportation Department has improved parts of I-84 in Boise, Idaho. These desired improvements led to the widening of a bridge over the New York Canal (NYC) in 2009. To support the wider road, additional bridge columns were installed. The new bridge columns had a larger diameter than the existing columns and raised the number of columns from 28 to 60.

Construction was completed just before the irrigation season began. During the first irrigation season it was observed that waves and oscillations were occurring within the canal immediately adjacent to the bridge structure. Throughout the irrigation season, it was observed that the intensity of the oscillations would vary. It was also observed that the wave oscillations propagated upstream and downstream from the bridge structure. Both longitudinal and transverse waves were observed. The waves appeared to originate in the section of the canal that was under the I-84 Bridge.

A physical model was built in 2010 at Utah State University's (USU) Utah Water Research Laboratory (UWRL) in an attempt to simulate the oscillation phenomenon and to develop potential solutions to the problem. During the original modeling work, a thorough investigation to the causes of this phenomenon was not accomplished due to time constraints. The objective of the follow-up research presented in this thesis was to qualitatively determine the causes of the oscillations. Laboratory tests were performed using the original physical model used in the original 2010 testing.