Installation and Long Term Performance of Carbon Fiber Strands on the Penobscot Narrows and Observatory Bridge

The Penobscot Narrows and Observatory Bridge will be completed in early 2007. This bridge is using a new innovative cradle stay system that provides a continuous cable stay from the main span bridge deck anchorage, up through the cradle in the pylon and back down to the back span bridge deck anchorage. There are 50 to 70 strands per stay. Each strand passes through individual 1-inch diameter stainless steel sleeves that are bundled in a 16-inch diameter stay cradle pipe assembly. There are 20 stay cradles encased in each of the two upper pylons. The epoxy-coated strands that pass through the free length of the stays between the deck and the pylon cradle are housed in an HDPE sheath. Four levels of stay protection are provided with this system that includes: 1. epoxy coated strand in the stay 2. HDPE stay sheathing 3. inert nitrogen gas injected under 2 psi of pressure 4. monitoring system with gas gages, gas recharge tanks and dyna-force gages. This cable stay system includes extra reference strands in each stay that may be removed for inspection and replaced or remain removed from the system. It is proposed that two CFRP (carbon fiber reinforced polymer) strands in each of three stays, for a total of six strands be initially installed as reference strands along with a defined monitoring and investigation program. These CFRP strands will be stressed to the similar levels as the surrounding epoxy-coated strands in the respective stays. A strain monitoring system will provide a wealth of real-time data that can be subsequently analyzed and compared to the original design parameters. This proposed program provides a unique opportunity to incorporate a durable CFRP strand material into this innovative cable stay system. This is a special opportunity for evaluating long-term performance of this strand material under real service conditions in a harsh Maine environment that can provide a benchmark in the United States for possible use of strands manufactured with this material in future cable stayed bridges. Funds for this project are from FHWA Innovative Bridge Research and Deployment Program.

  • Supplemental Notes:
    • A second report is being generated to document additional analysis and propose a long term monitoring and evaluation plan


  • English


  • Status: Completed
  • Sponsor Organizations:

    Maine Department of Transportation

    16 Statehouse Station
    Augusta, ME  United States  04333
  • Start Date: 20061201
  • Expected Completion Date: 0
  • Actual Completion Date: 20091201
  • Source Data: RiP Project 12561

Subject/Index Terms

Filing Info

  • Accession Number: 01506741
  • Record Type: Research project
  • Source Agency: Maine Department of Transportation
  • Files: RIP, STATEDOT
  • Created Date: Feb 8 2014 1:01AM