Monitoring of a Bascule Bridge during Construction

The risk of member/connection distress or even overall collapse of bridge structures under significant rehabilitation efforts is generally greater than when subject to normal operating conditions and hazards. This is particularly evident for movable structures. Currently, visual inspection during construction is the most common source of assurance a bridge owner has that the structure is functioning properly. Complex structures like movable bridges may benefit from additional oversight beyond visual inspection because of the elevated risks. Structural health monitoring of critical elements can help reduce these risks. A case study is presented for the first monitoring effort of a rolling lift bascule bridge under rehabilitation. During an opening of the span for ship traffic, a 460µε (92MPa or 13.3ksi) shift in strain response was measured in the truss lower chord. To identify the root cause of this behavior, a detailed investigation was performed including field studies, interviews and model-experiment correlation. It was concluded that a connection slip occurred at a partially completed repair. Fortunately the structural system utilized on this bascule span includes a redundant truss which allowed for redistribution of forces. In this scenario, the primary impact of the monitoring was a change to the construction sequence allowed by the contractor. This investigation shows the potential benefit of instrumentation and monitoring in conjunction with traditional visual assessment methods, specifically during construction and retrofit of a movable bascule bridge.

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• Supplemental Notes:
  • This paper was sponsored by TRB committee AFF10 Standing Committee on General Structures.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Yarnold, Matthew
  • Weidner, Jeffrey
• Conference:
  • Transportation Research Board 95th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2016-1-10 to 2016-1-14
• Date: 2016

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 15p
• Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Bascule bridges; Bridge construction; Instrumentation; Structural health monitoring
• Uncontrolled Terms: Visual assessment study
• Subject Areas: Bridges and other structures; Construction; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01593572
• Record Type: Publication
• Report/Paper Numbers: 16-5822
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Mar 15 2016 10:10AM