High-Mast Tower Foundation – Phase II

Details

• Creators:
  Al Maabreh, Ammar ; Awawdeh, Abdelrahman ; Maguire, Marc ; Puckett, Jay A. ; Kreiling, Brandon
• Corporate Creators:
  University of Nebraska-Lincoln ; Nebraska Transportation Center
• Corporate Contributors:
  Nebraska. Dept. of Roads. Research Section ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Best Practices High Mast Lighting Lighting Lighting Columns Literature Reviews Street Lighting
• Publication/ Report Number:
  SPR-FY23(013)
• Resource Type:
  Tech Report
• Geographical Coverage:
  Nebraska;United States
• Edition:
  Final Report October 2022 – September, 2024
• Corporate Publisher:
  Nebraska. Department of Transportation
• Abstract:
  Challenge: High-mast luminaire supports used in the US transportation sector are typically steel poles that are attached to a baseplate via a butt or socket weld. Many have failed primarily due to fatigue cracking at the weld toe. Significant research in the US improved the fatigue performance of these structures; however, failures still occur due to high-cycle cracking at the weld toes, or at other fatigue-prone details. Additionally, poles are failing in moderate winds that create galloping. Galloping is an aerodynamic phenomenon where the wind excitation frequency matches the pole’s natural frequency creating resonance. The top amplitudes are many times the pole tip diameter, e.g., 30 ft one way due to the inherently low damping. These movements and associated strains create low-amplitude fatigue (repeated yielding) typically causing the pole to fall. Alternative design: An alternative to the traditional design is to directly embed the pole into a foundation shaft and backfill with concrete or gravel. This eliminates the fatigue-prone details associated with baseplates, welds, bolts, anchorages, and rebars. This process is routinely used in the electrical utility, telecom, and sports-lighting sectors. It can potentially remove the fatigue issue, provide a cheaper fabrication and construction method, and increase damping. Research: This research was conducted in two phases: Phase I reviewed the literature, specifications, best practices, and construction methods. Phase II used this work to design, construct, and test four poles to near failure. Phase II work is the focus of this report.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:1477166f0abbdd01e04d287fb400c253d45489eb1fd6adeb14c37b64b6b871a6dae3cf8c45a9636dde6c44a9ba85a461db4960b813e3b68a2edc1f244e4e3ac9
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/80136/dot_80136_DS1.pdf
• File Type:
  [PDF - 16.26 MB ]