Research & Innovation

Phase I: Re-tightening the Large Anchor Bolts of Support Structures for Signs and Luminaires

Summary:

Roughly 20 percent of MnDOT's inventory of anchor bolts for sign structures, light towers and traffic signals may be loose at any given time. Researchers examined specifications and procedures for tightening anchor bolts in Minnesota, and conducted lab and field tests on new approaches tailored to various bolt-and-nut configurations. New specifications and instructions will help crews lubricate and tighten bolts properly and ensure lasting safety of signs and lights in Minnesota's highway system. Numerical models will allow anchor configurations that may be adopted in the future.

Final Deliverables:

• Re-tightening the Large Anchor Bolts of Support Structures for Signs and Luminaires (Report #2018-27)
• Improved Specifications for Tightening Anchor Bolts on Signs, Luminaires and Traffic Signals (Research Summary)

Related Materials:

Related Research:

• Implementation of New Guidelines in Tightening Large Anchor Bolts of Supports for Signs & Luminaires
• Re-tightening the Large Anchor Rods of Support Structures for Signs and Luminaires: Phase II

Project Personnel:

Principal Investigator:  An Chen
Co-Principal Investigator:  Behrouz Shafei
Technical Liaison:  Jihshya Lin
Project Coordinator:  Debra Fick
Panel Members: 
    Christian Hoberg - Metro District
    Douglas Maki - Asset Management
    Eric Embacher - Metro District
    Eric Evens - Bridges
    Josephine Tayse - Traffic Engineering
    Mark Taylor - Metro District
    Matthew Pooler - Metro District
    Mijia Yang - North Dakota State University
    Patrick O'Brien - Metro District
    Susan Zarling - Traffic Engineering
    Todd Niemann - Bridges
    Travis Hosteng - Iowa State University
    Trisha Stefanski - Asset Management
    Zhibin Lin - North Dakota State University