Field Observations and Evaluations of Streambed Scour at Bridges (Paperback) (ISBN-13: 9781508836582)

Bridge piers and highway embankments leading to a bridge often obstruct the flow of floodwaters, causing an increase in velocity and the development of vortices. The increased velocity and vortices often cause scour near the bridge foundations. The damage to and failure of bridges caused by scour are problems of national concern. This report describes the results of the second USGS national field-data collection and analysis study on scour at bridges, funded by FHWA. The database originally developed during the first national study has been enhanced and many scour measurements added, including measurements of abutment and contraction scour. Sufficient local pier scour data are now available to permit a detailed analysis of local pier scour. Scour depths computed from published pier scour equations are compared to the field measurements. Many commonly cited dimensionless variables believed to control the depth of scour are evaluated and compared with equations developed from laboratory data. The effect of the size and gradation of the bed material on the depth of scour is investigated, and a correction factor for the HEC-18 pier scour equation is proposed. Available data are insufficient to permit a detailed investigation of contraction and abutment scour; however, some basic comparisons and qualitative observations are presented on the basis of a review of the literature. The results of scour analyses for two contracted bridges are compared with real-time field data.

Author: Federal Highway Administration,U. S. Department of Transportation
ISBN-10: 1508836582
ISBN-13: 9781508836582
Publisher: Createspace Independent Publishing Platform
Language: English
Published: 03/12/2015
Pages: 140
Format: Paperback
Weight: 0.75lbs
Size: 11.02h x 8.50w x 0.30d