United States Department of Transportation
ROSA P serves as an archival repository of USDOT-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by USDOT or funded partners.
As a repository, ROSA P retains documents in their original published format to ensure public access to scientific information.
[PDF-15.80 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Contributors:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Third Edition
-
Contracting Officer:
-
Corporate Publisher:
-
Abstract:inspection of bridges for scour. It contains updated material not included in the second edition dated April 1993. This document is a revision to HEC-18 dated April 1993 which, in turn, was an update of HEC-18 dated February 1991 and of the publication, “Interim Procedures for Evaluating Scour at Bridges,” issued in September 1988 as part of the FHWA Technical Advisory T 5140.20, “Scour at Bridges.” T 5140.20 has since been superseded by T 5140.23, “Evaluating Scour at Bridges” dated October 28, 1991, This document contains revisions obtained from further scour-related developments and use of the 1993 edition of HEC- I8 by the highway community. The principal change from the 1993 edition of HEC-18 is the use of metric (SI) units of measurement. Additional changes are: a discussion of backwater effects on contraction scour and the use of the water surface or the energy grade line as the reference line for measuring contraction scour depths, addition of a coefficient to the pier scour equation to account for the armoring effect of large particle sizes in the bed material, and addition of an equation to compute the coefficient applied to the pier scour equation when there is an angle of attack. Figures have been added to clarify computation of pier scour for exposed footings, pile caps placed in the flow, multiple columns skewed to the flow, and scour resulting from pressure flow. This document includes a method to compute scour depths for pressure flow when a bridge deck is submerged. A method to compute AH for constricted tidal waterways is given along with the procedure used by Maryland SHD to evaluate scour for bridges over tidal waterways. A discussion of computer models to determine the value of the hydraulic variables for scour analysis of bridges over tidal waterways has been added and information on scour detection equipment has been updated based on recent research. Finally, minor errors in the text and figures have been corrected.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
