Sediment erosion in the region of bridge piers is a potential hazard to the safety of bridges. The presence of various roughness heights on the surface of bridge piers as a scour countermeasure was explored. Laboratory experiments under clear-water conditions were conducted using four roughness heights with three pier diameters under four different flow water depths. The test program included a case of a smooth pier to determine the performance of the roughened piers and to benchmark some existing formulas of local scour around bridge piers. Although the roughened piers produced an extended scour hole length upstream of the bridge piers, results revealed the effectiveness of the roughened piers in decreasing the maximum scour depth, angle of upstream slope, planner area, and volume of the scour hole upstream of the pier. An empirical formula was developed to determine the maximum scour depth for the roughened piers. |
