Reduction of Bend Scour by an Outer Bank Footing: Flow Field and Turbulence

• Published in: Journal of hydraulic engineering (New York, N.Y.) Vol. 135; no. 5; pp. 361 - 368
• Main Authors: Roca, M, Blanckaert, K, Martín-Vide, J. P
• Format: Journal Article
• Language: English
• Published: Reston, VA American Society of Civil Engineers 01.05.2009
• Subjects: Applied sciences; Buildings. Public works; Earthwork. Foundations. Retaining walls; Exact sciences and technology; Geotechnics; Hydraulic constructions; Port facilities and coastal structures. Lighthouses and beacons; River flow control. Flood control; TECHNICAL PAPERS; Turbulence; Bank; Footing; Hydraulics; Stabilization; Rivers; Bends; Experimental study; Flow field; hydraulic; Scour; Secondary flow; Turbulence; River bank stabilization; Velocity distribution; Flow regime; Protection system; Topography; Scour; Secondary flow
• ISSN: 0733-9429; 1943-7900; 1943-7900
• DOI: 10.1061/(ASCE)HY.1943-7900.0000028

River bank protection is a costly but essential component in river management. Outer banks in river bends are most vulnerable to scour and erosion. Previous laboratory experiments illustrated that a well-designed horizontal foundation of a vertical outer bank protruding into the cross section, called a footing, can reduce the scour depth and thereby protect the bank. This paper provides detailed experimental data in a reference experiment without footing and an experiment with footing carried out under similar hydraulic conditions, which suggest a delicate interaction between bed topography, downstream and cross-stream velocity, and to lesser extent turbulence. The presence of the outer bank footing modifies this delicate interaction and results in a more favorable configuration with respect to bank stability including: reduced maximum scour depth, more uniformly distributed downstream velocity, and weaker cross-stream circulation cells.