Fatigue performance of variable message sign & luminaire support structures : volume II, fatigue related wind loads on highway support structures.

Details

• Creators:
  Consolazio, Gary R. ; Johns, Kevin W. ; Dexter, Robert J.
• Corporate Creators:
  New Jersey Department of Transportation
• Corporate Contributors:
  Lehigh University. ATLSS Engineering Research Center
• Subject/TRT Terms:
  • Traffic signs
  • Structures
  • Structural supports
  • Fatigue (Mechanics)
  • Wind
  • Variable message signs
  • Traffic signs and signals--New Jersey--Aerodynamics
  • Wind-pressure
• Publication/ Report Number:
  FHWA 1998-010
• Resource Type:
  Tech Report
• Geographical Coverage:
  New Jersey
• Edition:
  Final report; Sept. 1996-June 1998.
• Corporate Publisher:
  New Jersey. Dept. of Transportation
• Abstract:
  In Order to determine equivalent static pressures for fatigue loads on cantilevered highway support structures a ; cantilevered Variable Message Sign(VMS) located along Interstate westbound at mile marker 48.5 in northern ; New Jersey was continuously monitored for three months. The structure was instrumented with strain gages, ; pressure transducers, and a wind sentry. All the data was collected with a Campbell Scientific CR9000 digital ; data acquisition system. A cellular phone transceiver enabled remote communication with the data logger. The ; system and instrumentation was powered with solar powers and marine batteries. Short-term testing was ; performed on the structure to determine the dynamic characteristics such as stiffness, natural frequency, and ; percent of critical damping. Results of the short-term test indicated that the stiffness was 0.24 kN/mm, the first ; and the second modes were 0.87 cycles/s and 1.22 cycles/s respectively, and the percent of critical damping for ; the first and second modes were 0.57 percent and 0.25 percent respectively. Long-Term monitoring was ; performed to capture the structures response to natural wind gusts, galloping, and truck-induced wind gusts. This ; data would then be used to determine appropriate fatigue design wind loads for future sign support structures. ; During the three months of monitoring the structure did not experience galloping, which is a phenomena highly ; dependent on location. A galloping design pressure of 1000 Pa was recommended based on previous research. ; The summer months, which is when the structure was monitored, were not conductive to the strongest natural ; winds patterns in Northern New Jersey. The highest natural wind speed that was recorded was 7.5m/s. It is ; believed that much stronger winds are present in winter and spring, therefore a natural wind gust design ; pressure of 250 Pa was recommended. Truck-induced gusts were measured and a linear gradient for the truckinduced ; gust design pressure was determined. The truck-induced gust design pressure ranged linearly from ; 1760 Pa at 0 to 6m above the surface of the road to 0 Pa at 10.1m and over.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18369/dot_18369_DS1.pdf
• File Type:
  [PDF - 7.54 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:5a1932a405980a0aa59ed5dbbf9977235afde2af48cbeb94719d25fa4c94099b