Methods To Ensure Appropriate Installation And Prevent Loosening Of Anchor Nuts On Ancillary Highway Structures

In recent years, the Virginia Department of Transportation and other highway agencies have experienced recurring problems of anchor bolt nuts discovered to be loose on ancillary highway structures. The cause of loosening is unknown and the structures vary widely in type, age, size, and material. This study will investigate the causes of loose nuts on anchor bolts and isolate parameters that may contribute to this behavior. Parameters to be investigated include the anchor rod diameter, nut and anchor configuration details, thread fabrication method, thread tolerance, and material type(s). In addition, methods to appropriately tighten and evaluate the in-situ pretension of anchor nuts will be investigated. The required tension for anchor rods connected to aluminum structures, which are currently not addressed in any specifications, will be evaluated and reported. The research will provide guidance on how to prevent the loosening of anchor nuts.


    • English


    • Status: Active
    • Funding: $449700
    • Contract Numbers:


    • Sponsor Organizations:

      Virginia Transportation Research Council

      530 Edgemont Road
      Charlottesville, VA  United States  22903
    • Performing Organizations:

      Virginia Polytechnic Institute and State University, Blacksburg

      208 Patton Hall
      Blacksburg, VA  United States  24061
    • Principal Investigators:

      Hebdon, Matt

    • Start Date: 20161201
    • Expected Completion Date: 20200531
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01616441
    • Record Type: Research project
    • Source Agency: Virginia Department of Transportation
    • Contract Numbers: 110326
    • Files: RIP, STATEDOT
    • Created Date: Nov 21 2016 9:16AM