Effects of developing ice covers on bridge pier scour
Dario A. B. Sirianni, Christopher Valela, Colin D. Rennie, Ioan Nistor, Husham Almansour
Abstract
Current research investigating ice-covered bridge pier scour has focused on the effects of fully developed ice jams. However, based on observationsat various stages of development, ice covers are not always fully developed. This experiment investigated pier scour at various stages of a simulatedfloating ice jam’s development, with a constant flow rate. Various channel-spanning ice cover lengths were tested, along with one circular localizedcover, and resulting pier scour was compared to free-surface flow pier scour. Five lengths of downstream initiated ice covers were tested, withlengths upstream of the pier being 0, 0.63, 1.33, 2.66 and 5.32 m. The local cover’s diameter was 0.27 m, three times the pier diameter. The 2.66-mice cover produced the greatest scour and near-bed Reynold stress, with greater scour depth and volume, respectively, by 46.9% and 238% comparedto free-surface flow conditions, whereas the local cover produced the smallest scour increase.