Parallel Walls as an Abutment Scour Countermeasure

Abstract

Scour at bridge abutments can cause damage or failure of bridges and result in excessive repairs, loss of accessibility, or even death. To mitigate abutment scour, both clear-water and live-bed laboratory experiments in a compound channel were performed using parallel walls. Two types of parallel walls were tested: the first was made of a solid thin wood plate and the second was made of piled rocks. For solid parallel walls, a series of vertically oriented, rectangular, straight plates of different lengths attached to the upstream end of a wing wall abutment parallel to the flow direction were employed. Three velocities of 0.9, 1.5, and 2.3 times the incipient motion value for bed sediment movement were used. The bed material was sand with a mean diameter of