High-mast light poles anchor nut loosening in Alaska : an investigation of field monitoring and finite-element analysis.

Details

• Creators:
  Hamel, Scott ; Hoisington, David
• Corporate Creators:
  Alaska University Transportation Center
• Corporate Contributors:
  United States. Dept. of Transportation. Research and Innovative Technology Administration ; Pacific Northwest Transportation Consortium
• Subject/TRT Terms:
  • High mast lighting
  • Poles (Supports)
  • Anchor bolts
  • Nuts (Fasteners)
  • Field studies
  • Finite element method
  • Foundations
  • Strain (Mechanics)
  • Pretensioning
• Publication/ Report Number:
  INE/ AUTC 14.13 ; DOT&PF Report No. 4000117
• Resource Type:
  Tech Report
• Geographical Coverage:
  Alaska
• Corporate Publisher:
  Alaska. Dept. of Transportation and Public Facilities
• Abstract:
  High mast lighting poles (HMLPs) are tall, roadside structures effective for lighting large areas of highways and intersections. The Alaska Department of Transportation ; and Public Facilities (AKDOT&PF) maintains 118 such poles in the greater Anchorage and Fairbanks areas. Some of these HMLPs have experienced anchor nut ; loosening at their foundation connection and an in-depth review of inspection reports suggests that the foundation type and the number of anchor rods affect loosening. ; In this study, two HMLPs were field instrumented and the axial force in their anchor rods was recorded during tightening. Excessively high anchor rod pre-tensions were ; recorded on the first pole, after which a modified tightening procedure was created and used successfully on the 2nd ; pole. Finite-element (FE) modeling was conducted to ; examine the mechanical behavior of the foundation connections and recreate the clamp-load loss. ; The monitoring and modeling results indicate that plastic deformation of the anchor rods is the likely cause of clamp-load loss in flange-type connections. Anchor rods in ; double nut moment connections, high strength rods, and increased flange plate thickness were all shown to reduce clamp-load loss. Recommendations for existing and yet ; to be installed HMLPs are presented based on these results.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28147/dot_28147_DS1.pdf
• File Type:
  [PDF - 4.79 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:d93a81b866912051f8f84849c76d08cb614576a10f08477a12079bdb5cd13a8b