Details:

Creators:
Feaster, Toby D. ; Benedict, Stephen T. ; Caldwell, Andral W.
Feaster, Toby D. ; Benedict, Stephen T. ; Caldwell, Andral W. Less -
Corporate Creators:
South Carolina. Dept. of Transportation
Corporate Contributors:
Geological Survey (U.S.)
Subject/TRT Terms:
[+]
Bridges Curves (Geometry) Equations Scour
Publication/ Report Number:
Fact Sheet 2016-3065
DOI:
http://dx.doi.org/10.3133/fs20163065
Resource Type:
Tech Report
Geographical Coverage:
South Carolina
ISSN:
2327-6932
Corporate Publisher:
Geological Survey (U.S.)
Abstract:
Bridge-scour equations presented in the Federal Highway Administration Hydraulic Engineering Circular No. 18 reflect the current state-of-the practice for predicting scour at bridges. Although these laboratory-derived equations provide an important resource for assessing scour potential, there is a measure of uncertainty when applying these equations to field conditions. The uncertainty and limitations have been acknowledged by laboratory researchers and confirmed in field investigations.

Because of the uncertainty associated with bridge-scour equations, HEC-18 recommends that engineers evaluate the computed scour depths obtained from the equations and modify the resulting data if they appear unreasonable. Perhaps the best way to evaluate the reasonableness of predicted scour is to compare it to field measurements of historic scour. Historic field data show scour depths resulting from high flows and provide a reference for evaluating predicted scour. It is rare, however, that such data are available at or near a site of interest, making the evaluation of predicted scour as compared to field data difficult if not impossible. Realizing the value of historic scour measurements, the U.S. Geological Survey (USGS), in cooperation with the South Carolina Department of Transportation (SCDOT), conducted a series of three field investigations to collect historic scour data with the goal of understanding regional trends of scour at riverine bridges in South Carolina.

Historic scour measurements, including measurements of clear-water abutment, contraction, and pier scour, as well as live-bed contraction and pier scour, were made at more than 200 bridges. These field investigations provided valuable insights into regional scour trends and yielded regional bridge-scour envelope curves that can be used as supplementary tools for assessing all components of scour at riverine bridges in South Carolina.

The application and limitations of these envelope curves were documented in four reports. Because each report addresses different components of bridge scour, it was recognized that there was a need to develop an integrated procedure for applying the envelope curves to help assess scour potential at riverine bridges in South Carolina. The result of that effort is detailed in Benedict and others (2016) and summarized in this fact sheet.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:ce283d47bb5f2475f5229b39e360379e346e6748ccd2bd574478bf32a78697ae
Download URL:
https://rosap.ntl.bts.gov/view/dot/43781/dot_43781_DS1.pdf
File Type:

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