Sensor-assisted Condition Evaluation of Steel and Prestressed Concrete Girder Bridges Subjected to Fire – Phase III

The overarching goal of this multi-phase study is to develop and validate a post-fire condition evaluation method for steel- and prestressed concrete-girder bridges (overpasses or viaducts) based on material and structural data, a fire scenario (e.g., a fuel tank on highway), and environmental factors (e.g., moisture and wind). The proposed method involves fire dynamics simulation underneath a bridge, thermomechanical analysis of the structure, and structural condition assessment against material strengths. One of the key challenges to achieve this goal is to measure strains in steel members on fire and detect concrete cracks in order to validate various computational models. Phases I and II of this study aimed to understand and validate the performance of distributed fiber optic sensors based on Brilliouin optical time domain analysis (BOTDA) for temperature and strain measurements in reinforced concrete (RC) bridges, and develop and validate a fire dynamics simulator and a thermomechanical model with measured data. In particular, the deployment scheme and data quality of distributed sensors embedded in concrete and attached on steel members are evaluated. The effects of multiple steel girders on the aerodynamics and heat distribution of a fire are investigated through fire dynamics and thermomechanical analysis. Phase III of this study aims to understand the performance and behavior of prestressed concrete girders under a fire and quantify the prestress loss over time using distributed fiber optic sensors such as BOTDA. Due to uncertain bonding between an optical fiber and concrete, strain measurements based on the transfer of strain from concrete to the optical fiber are less reliable particularly to determine the loss of prestress in tendon. Therefore, a new distributed fiber optic acoustic sensing system will be used to detect cracks developed in proximity of the concrete-tendon interface.

    Language

    • English

    Project

    • Status: Active
    • Funding: $165196
    • Contract Numbers:

      69A3551747107

    • Sponsor Organizations:

      Mid-America Transportation Center

      University of Nebraska-Lincoln
      2200 Vine Street, PO Box 830851
      Lincoln, NE  United States  68583-0851

      Office of the Assistant Secretary for Research and Technology

      University Transportation Centers Program
      Department of Transportation
      Washington, DC  United States  20590
    • Managing Organizations:

      Mid-America Transportation Center

      University of Nebraska-Lincoln
      2200 Vine Street, PO Box 830851
      Lincoln, NE  United States  68583-0851
    • Project Managers:

      Stearns, Amy

    • Performing Organizations:

      Missouri University of Science & Technology, Rolla

      Department of Engineering
      202 University Center
      Rolla, MO    65409
    • Principal Investigators:

      Chen, Genda

    • Start Date: 20191213
    • Expected Completion Date: 20201231
    • Actual Completion Date: 0
    • USDOT Program: University Transportation Centers Program

    Subject/Index Terms

    Filing Info

    • Accession Number: 01738626
    • Record Type: Research project
    • Source Agency: Mid-America Transportation Center
    • Contract Numbers: 69A3551747107
    • Files: UTC, RiP
    • Created Date: Feb 11 2020 12:18PM