Monitoring vibrations on the Jefferson City Truss Bridge.

Details

• Creators:
  Washer, Glenn A. ; Fabian, Pedro Ruiz ; Dawson, James
• Corporate Creators:
  University of Missouri--Columbia. Department of Civil and Environmental Engineering
• Corporate Contributors:
  Missouri. Department of Transportation. Construction and Materials Division ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Accelerometers
  • Data collection
  • Recommendations
  • Truss bridges
  • Trusses
  • Vibration
  • Weather conditions
  • Wind
  • Data analysis
  • resonance frequency
  More +
• Publication/ Report Number:
  cmr 16-012
• DOI:
  http://dx.doi.org/10.13039/100007251
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Missouri
• Edition:
  Final report, August 2015-February 2016
• Corporate Publisher:
  Missouri. Department of Transportation
• Abstract:
  The objective of the research was to determine the frequency and cause of resonant vibrations of truss verticals on bridge A4497 ; over the Missouri River in Jefferson City, MO. Instrumentation to monitor the vibrations of four verticals was installed on the ; bridge and monitored for 42 days. The instrumentation consisted of wireless accelerometers that monitored the accelerations on ; the four verticals. Weather data available from a weather station located at the Jefferson City Airport was used to analyze the ; weather conditions causing resonant vibrations of the verticals. It was found that there were eleven vibration “events” in which the ; vertical members vibrated with higher than normal accelerations. The average wind speeds during the events was about 17 mph. ; The wind direction during the events was from the WNW/NW during nine of the “events” and from the SE for 2 of the “events.” ; It was found that the frequency of the events was 0.26 events per day during the monitoring period. ; Historical weather data was analyzed to determine how frequently the resonance vibrations may be occurring, i.e., how frequently ; the combined wind speed and direction matched the conditions determined through the field monitoring. Historical weather data ; from 442 days was analyzed and it was found that there were 89 occurrences of the combined wind speed and direction that could ; cause vibrations of the vertical members. The resulting frequency of events was determined to be 0.20 events per day. ; It was concluded that the frequency of resonant vibration events is likely 0.25 events per day or less. The vibrations are caused by ; average winds from the WNW/NW or SW of ~17 mph or greater, based on monitoring results. Recommendations stemming from ; the research were as follows: 1) The effect of the vibration events on the durability of the members should be analyzed further to ; determine if a retrofit is necessary. The data provided through the field monitoring should be used in the analysis; and 2) Other ; vertical members of a similar length should be monitored to determine if they are affected by resonant vibrations.
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• Format:
  PDF
• Funding:
  MoDOT project #TR201605
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/31048/dot_31048_DS1.pdf
• File Type:
  [PDF - 2.78 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:3f609d371d2bea1b7bafbce898ad56558c84ca699db8c861c1580fd35db55151