Author(s): N. L. Ackermann; H. T. Shen; P. Olsson
Linked Author(s): Hung Tao Shen
Keywords: No Keywords
Abstract: This paper presents a laboratory investigation on the effect of ice cover on local scour around circular bridge piers. Experiments were performed in a 12-meter flume with recirculating sediment discharge. Both smooth and rough artificial covers were used. The bed material consisted of uniform ripple-forming sand. The tests were run for both clear water as well as live bed conditions. The results showed that for equivalent averaged flow velocities the existence of an ice cover could increase the local scour depth scour by 25 to 35% from the free surface condition. The largest difference occurs at a live bed condition when the flow velocity, U, is in the rage of 1.5 to 2 times of the critical velocity for bed movement, Uc. A rough cover gives slightly larger scour depth than a smooth cover. The movement of bed forms led to variations of scour depth with time.
Year: 2002