Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Civil Engineering

First Advisor's Name

Ioannis Zisis

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Peter A. Irwin

Second Advisor's Committee Title

Co-Committee Chair

Third Advisor's Name

Ziad Azzi

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Arindam Gan Chowdhury

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

David Garber

Fifth Advisor's Committee Title

Committee Member

Sixth Advisor's Name

Wallied Orabi

Sixth Advisor's Committee Title

Committee Member

Keywords

cable supported traffic signal assembly, span wire traffic signal assembly, span wire traffic signals, traffic signal assembly, traffic signals, span wire, cable supported traffic signals, signal supports, hangers, messenger, catenary, strain poles assembly

Date of Defense

10-31-2022

Abstract

Hurricanes and high speed wind events in general are a major threat to all types of infrastructure. Especially vulnerable are miscellaneous roadway and highway structures that support signs and traffic signals throughout cities. These miscellaneous transportation structures are very important in keeping vehicular traffic flowing along roadways and through intersections. It is essential that these systems remain operable following wind events of this magnitude to aid in recovery and emergency response. The most sensitive to intense wind force damage are cable supported traffic signal systems. A large majority of traffic signalized intersections in Florida roads consist of cable supported systems and are vulnerable to powerful winds. Because of the vulnerability of these signal systems, Florida Department of Transportation (FDOT) has funded research to enhance the strength and serviceability.

Florida International University (FIU) Wall of Wind (WOW), a large wind research facility, has conducted tests of full scale span wire traffic signal assemblies to collect data to determine the dynamic response and the forces incurred by traffic signal components, i.e., hangers, disconnect boxes, etc., to wind induced forces.

Numerous experimental tests of full scale span wire signal assemblies were performed at WOW testing facility. The performance of various hanger support and disconnect box systems were observed. The first batch of tests conducted in 2015 and some in 2016 are reported as part of this dissertation along with an interpretation of their (hangers and disconnect boxes) response to different wind speeds.

This dissertation also presents numerical models that were developed which provide an evaluation of the forces, inclinations and wire deflections experienced by span wire traffic signal assemblies subjected to wind forces prior to unstable oscillations occurring. Results generated from the numerical models revealed that they were similar to the experimental results for wind speeds low enough not to initiate unstable oscillations.

Ultimately, the numerical models allow for the opportunity to learn about the response of these assemblies before instability occurs.

The final phase of this study presents a theoretical buffeting analysis of a span wire traffic signal assembly to estimate its buffeting response due to fluctuating wind velocity. The results from the analysis will be compared to experimental results obtained from tests conducted at the WOW. This analysis will produce information that will allow the evaluation of the magnitude of vibration that a span wire assembly goes through during fluctuating wind velocity. This information can give designers of span wire traffic signal assemblies a notion of the power of the vibration that these assemblies are subjected to.

Identifier

FIDC010953

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