Structural Monitoring and Maintenance Volume 1, Number 4, December 2014 , pages 393-409 DOI: https://doi.org/10.12989/.2014...393 |
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Effectiveness of strake installation for traffic signal structure fatigue mitigation |
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Kyle T. Wieghaus, Stefan Hurlebaus and John B. Mander
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Abstract | ||
Across-wind response is often the cause of significant structural vibrations that in turn cause fatigue damage to welded and other connections. The efficacy of low-cost helical strakes to mitigate such adverse response is presented for a traffic signal structure. Field observations are made on a prototype structure in a natural wind environment without and with helical strakes installed on the cantilevered arm. Through continuous monitoring, the strakes were found to be effective in reducing across-wind response at wind speeds less than 10 m/s. Estimates of fatigue life are made for four different geographical locations and wind environments. Results for the class of traffic signal structure show that helical arm strakes are most effective in locations with benign wind environments where the average annual wind speed is not more than the vortex shedding wind speed, which for this investigation is 5 m/s. It is concluded that while strakes may be effective, it is not the panacea to mitigating connection fatigue at all locations. | ||
Key Words | ||
traffic signal structure; fatigue; helical strakes; vortex shedding; full-scale monitoring | ||
Address | ||
Kyle T. Wieghaus, Stefan Hurlebaus and John B. Mander: Zachry Department of Civil Engineering, Texas A&M University, College Station, Texas 77843, USA | ||