Distribution of Water-Resources Investigations Report 96-4310, Method for Rapid Estimation of Scour at Highway Bridges Based on Limited Site Data, by Stephen R. Holnbeck and Charles Parrett


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        "B  - Branch Chiefs and Offices",
        "FO - State, District, Subdistrict and other Field Offices",
        "PO - Project Offices"
cc: "Annette L Ledford, Clerk Typist, Reston, VA ",
        " , WRD Archive File, Reston, VA "
Subject: OSW Technical Memorandum No. 97.04
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Date: Thu, 26 Jun 1997 10:58:51 -0400
From: "Annette L Ledford, Clerk Typist, Reston, VA "


In Reply Refer To:                                          June 23, 1997
Mail Stop 415


OFFICE OF SURFACE WATER TECHNICAL MEMORANDUM NO. 97.04

Subject:  Distribution of Water-Resources Investigations Report 96-4310,
          Method for Rapid Estimation of Scour at Highway Bridges Based
          on Limited Site Data, by Stephen R. Holnbeck and Charles 
          Parrett

This memorandum announces the availability of Water-Resources 
Investigations Report 96-4310, "Method for rapid estimation of scour at 
highway bridges based on limited site data," by Stephen R. Holnbeck and 
Charles Parrett. In a study partially funded by the Office of Surface 
Water, the authors have presented a method for more quickly and cost 
effectively making scour-depth estimates at bridges.

Data from detailed bridge-scour studies for 122 sites in 10 States, 
representing widely varying conditions, were compiled and analyzed by the 
U.S. Geological Survey to develop the method. Scour data obtained from 
the detailed studies, including scour depth that might occur due to a 
100-year flood, and other important characteristics like flow depth and 
velocity, were used to develop prediction curves. The curves were 
developed with a conservative philosophy so that estimates of scour depth 
would be as much or more than estimates obtained by detailed methods. The 
acceptability of the method was confirmed when results for a number of 
bridge sites where the rapid-estimation method was applied were compared 
against results obtained by detailed methods at the same sites, and good 
agreement was demonstrated. The report describes the methods used to 
obtain the required site data so the prediction curves can be applied to 
any site in the United States. Although the method is useful for 
identifying potentially scour-critical bridges, it does not replace 
detailed methods used for design purposes. Use of the rapid-estimation 
method should be limited to individuals having experience in bridge 
scour, hydraulics, and flood hydrology and some training in use of the 
method.

A limited supply of this report is available from the Office of Surface 
Water. Please call (703)648-5301. Otherwise contact the U.S. Geological 
Survey, Branch of Information Services, Box 25286, Denver, CO 80225-0286 
or call (303) 202-4210.


                                 /signed/

                                Ernest F. Hubbard
                                Assistant Chief, Office of Surface Water

WRD Distribution: A, B, FO, PO