Dynamic Analysis of the Bentley Creek Bridge with FRP Deck

This report investigates vibration characteristics of a truss bridge with a Fiber Reinforced Polymer (FRP) deck. The Bentley Creek Bridge is located in Wellsburg, Chemung County, New York. It is a 140-ft long through truss structure, originally built with a non-composite concrete deck. The concrete deck was replaced with a much lighter Fiber Reinforced Polymer (FRP) deck to improve the bridge rating. This study investigates the changes in vibration characteristics of the bridge as a result of the deck replacement and impact of these changes on the structural behavior. Two finite element models were developed: the first to describe the bridge in its original condition with a concrete deck and the second to represent the structure in its current condition with an FRP deck. The FRP deck bridge model was validated using field test data under both static and dynamic loads. Results of the analyses are documented in this report. The results indicate that the fundamental frequency for the current structure with the FRP deck is about 45 percent higher than that for the original concrete deck structure. The computed bridge fundamental frequency correlated well to those obtained using free vibration data collected on two truss members. The fundamental bending mode in both cases (FRP deck and concrete deck) was identified by its shape and characteristic dominant vertical modal mass. Forces in selected truss members due to dead load and live load were also investigated using the finite element analysis. An AASHTO HS-20 truck crossing the structure on the east lane at 5, 15, 30, and 60 mph speeds was used to represent the live load. The results indicated that, when compared to the concrete deck bridge model, the FRP deck bridge model resulted in lower dead load forces, higher live load forces, lower total forces, and higher live load force ranges used in fatigue life estimates. Dynamic allowance was also determined for each of the selected members for both concrete and steel decks. For the concrete deck bridge, the calculated dynamic allowance is higher than that based on the AASHTO equation. Lower dynamic allowances were obtained for the FRP deck bridge.

• Record URL:
  • https://www.dot.ny.gov/divisions/engineering/technical-services/trans-r-and-d-repository/SR150Final.pdf?nd=nysdot
• 
• Corporate Authors:

  New York State Department of Transportation

  Transportation Research and Development Bureau, 50 Wolf Road
  Albany, NY  United States  12232

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Albers, William F
  • Hag-Elsafi, Osman
  • Alampalli, Sreenivas
• Publication Date: 2007-5

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 54p

Subject/Index Terms

• TRT Terms: Bridge decks; Dynamic structural analysis; Fiber reinforced polymers; Finite element method; Live loads; Mathematical models; Static loads; Truss bridges; Validation; Vibration
• Identifier Terms: Bentley Creek Bridge
• Uncontrolled Terms: Field data
• Geographic Terms: Wellsburg (New York)
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01356799
• Record Type: Publication
• Report/Paper Numbers: Special Report 150, FHWA/NY/SR-07/150
• Files: TRIS, USDOT, STATEDOT
• Created Date: Nov 11 2011 3:33PM