Establishing a Scour Monitoring

One of the most common causes of catastrophic bridge failures worldwide has been scour, a phenomenon by which the streambed supporting a bridge's substructure is eroded away by stream flow or tidal action. Over 60% of bridge failures in the U.S. are due to scour. The industry has made advances in both the prediction of bridge vulnerability to scour, and in the response to bridges found susceptible to scour. The FHWA has mandated the establishment of a plan of action for all scour critical bridges. The focus of this paper is ensuring the safety of the traveling public through one method—the establishment of a scour monitoring program. This program comprises data collection, data analysis, and the establishment of a prescribed set of procedures to be followed in case a "scour event" has occurred. The basic parts of a scour monitoring program consist of a theoretical analysis of bridge scour susceptibility, a substructure stability analysis, the determination of scour critical depths, an analysis of various scour countermeasure alternatives, the design and installation of a data collection and retrieval system, and a plan of action should any of a number of prescribed "trigger points" be met. Typically, diving inspections and fathometer surveys occur at intervals of up to five years; however, the scour monitoring program can provide around-the-clock assessment of the streambed elevations during a storm event, and transmit real-time data to those responsible for assessing the safety of bridge structures. This paper draws from active case studies involving three bridges on the South Shore of Long Island, New York, and the Woodrow Wilson Bridge over the Potomac River in Washington, DC. The following discussion spans the development and implementation of a scour monitoring program and the lessons learned.

Language

  • English

Media Info

  • Media Type: Web
  • Pagination: pp 1-11
  • Monograph Title: Geo-Frontiers 2005: Erosion of Soils and Scour of Foundations

Subject/Index Terms

Filing Info

  • Accession Number: 01886738
  • Record Type: Publication
  • ISBN: 9780784407813
  • Files: TRIS, ASCE
  • Created Date: Jun 29 2023 9:12AM