A STUDY OF ABUTMENT SCOUR

This report presents an investigation of local clear water scour at a wing wall abutment. The main objectives of the study were to measure the complex three dimensional flow field at the abutment and to determine the effect of flow depth on the velocity field and the choice of appropriate normalising parameter for abutment scour depth. The experimental programme was confined to steady state approach flow at near threshold conditions. An abutment length of 475 mm and a mean sediment size of 0.85mm in a 1.52m wide rectangular channel were used. The temporal scour development was monitored for flow depths of 50, 75, 100, 150 and 200 mm. Fixed-bed equilibrium scour models were constructed for flow depths of 75 and 150mm, and the hydrogen bubble technique was used for detailed qualitative and quantitative measurements of the three-dimensional flow at equilibrium conditions for these models. The experimental results have shown that the primary vortex and associated downflow are the dominant flow structures at the abutment. The secondary vortex is small and relatively weak. Flow patterns are relativley unaffected by changes in approach flow depth and are similar to those at piers. It is concluded that the abutment length is the appropriate normalising parameter for abutment scour depths, assuming that the abutment length to flow depth ratio is less than about 30.

• Corporate Authors:

  University of Auckland

  Private Bag
  Auckland 1,   New Zealand 
• Authors:
  • Kwan, T F
• Publication Date: 1988-7

Language

• English

Media Info

• Pagination: 467 p.
• Serial:
  • Issue Number: 451

Subject/Index Terms

• TRT Terms: Abutments; Bridges; Calculation; Depth; Flow; Fluid dynamics; Length; Scale models; Scour; Sediments; Shape; Speed; Structural models
• ITRD Terms: 3424: Abutment; 3455: Bridge; 6464: Calculation; 6499: Depth; 5275: Erosion; 5430: Flow (fluid); 6488: Length; 6205: Model (not math); 4190: Sediment; 9073: Shape; 5408: Speed
• Subject Areas: Bridges and other structures;

Filing Info

• Accession Number: 00604963
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Feb 28 1991 12:00AM