Remaining life assessment of in-service luminaire support structures : final report, January 2010.

Details

• Creators:
  Frymoyer, Mark ; Berman, Jeffrey
• Corporate Creators:
  Transportation Northwest (Organization)
• Subject/TRT Terms:
  • Street lighting
  • Luminaires
  • Structural supports
  • Structural members
  • Welds
  • Forecasting
  • Roads--Lighting--Supports--Washington (State)--Aerodynamics
  • Welded joints--Cracking--Washington (State)--Forecasting
• Publication/ Report Number:
  TNW2010-01
• Resource Type:
  Tech Report
• Geographical Coverage:
  Washington
• OCLC Number:
  664685082
• Edition:
  Final research report.
• Corporate Publisher:
  Transportation Northwest (Organization)
• NTL Classification:
  NTL-HIGHWAY/ROAD TRANSPORTATION-Bridges and Structures ; NTL-SAFETY AND SECURITY-Highway Safety
• Abstract:
  Recent fatigue failures of in-service luminaire support structures in Washington and around the country have ; prompted concern about their fatigue resistance. Most luminaire support structures in Washington were designed ; without attention to fatigue or with vague and incomplete fatigue design provisions. Furthermore, most luminaire ; support structures were installed during the construction of the Interstate system in the 1960s, and as many as half ; are estimated to have exceeded their 25-year design life. This research was initiated to help the Washington State ; Department of Transportation (WSDOT) prioritize the inspection and replacement of luminaire support structures ; throughout the state and to develop rational inspection procedures. ; The research had four primary components: a literature review, experimental fatigue testing of two in-service ; luminaire poles, a finite element analysis of the pole base, and development of a framework for estimating ; remaining life. The extensive literature review found previous experimental studies, which were used to identify ; details in older WSDOT luminaire support structures that may be critical and to help inform the selection of test ; specimens. Quasi-static and high cycle fatigue testing were performed on two previously in-service luminaire poles ; to determine the stress concentration factors (SCF) in critical details and determine fatigue resistance. The results ; were then compared to the finite element analysis and the fatigue classifications used in design. The finite element ; model was also used to determine the impact of parameters including base plate thickness, hand hole stiffener ; thickness, and location of anchor bolts. The individual components of a framework for estimating the remaining ; life of luminaire support structures in Washington were developed on the basis of a procedure established by Foley ; et al. (2004) in their study of the remaining life of sign bridge structures. ; The remaining fatigue life of the critical details in the previously in-service luminaire support structures were ; found to exceed their design life. Cracking at the stiffened hand hole detail was found to be the ultimate limit state ; for both specimens but was observed at cycle counts that were well beyond the design life. High SCFs were ; measured in both compression and tension at the CJP weld toe, indicating the importance of base plate flexibility, ; anchor bolt layout, and a uniform bearing surface. While it was not possible to know the load history for the ; selected specimens, it is clear that the number of damaging cycles was low and that the fatigue design life for these ; details is conservative. Recommendations for luminaire inspection are provided.
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• Format:
  PDF
• Funding:
  DTRT07-G-0010
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17555/dot_17555_DS1.pdf
• File Type:
  [PDF - 4.15 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:41ad995646eccafac2371462741becab673e44e2d828c8b3c552b719fd839f99