Shape Memory Alloy Enhanced SMART Expansion Joints

This Innovations Deserving Exploratory Analysis (IDEA) project developed a new shape memory alloy (SMA) enhanced modular expansion joint, or SMART joint, that can accommodate the heightened demands imposed during extreme events like earthquakes, while maintaining industry preferred thermal load behavior with minimal modifications to current bridge joint configurations. The joint selected for enhancement represents a commonly installed modular bridge expansion joint (MBEJ) whose equidistant system is supplemented with shape memory alloy springs designed to supply additional displacement capacity only during a seismic event, while avoiding additional load transfer in the system that may damage other components. These features open the door for easy integration of the joint into standard bridge design and specifications, and aim to streamline manufacture of the system. By taking advantage of the unique material properties of SMAs, the bridge joint can accommodate additional seismically induced longitudinal motions, under which the standard system is expected to fail. Without altering the industry accepted force deformation behavior related to the annual thermal movements and with minimal changes to the existing configuration of the subject bridge joint, the proposed shape memory alloy enhanced modular bridge joint is shown to outperform the standard modular bridge joint in experimental testing. The experimental verification of the SMART joint was also used to propose and validate an analytical model of the as-built and enhanced MBEJ. Subsequent analysis with the validated model, including nonlinear dynamic analysis and probabilistic assessment, demonstrate the improved fragility and reduced life-cycle costs that could be achieved with the enhanced joint. Therefore, this new class of bridge expansion joints equips the bridge industry with cost-effective system that promotes the post-event functionality of the joint and bridge system while reducing the associated life cycle costs.

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  • Supplemental Notes:
    • This NCHRP-IDEA investigation was conducted by William Marsh Rice University and the Georgia Institute of Technology. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
  • Authors:
    • Padgett, Jamie E
    • DesRoches, Reginald
  • Publication Date: 2013-7

Language

  • English

Media Info

  • Media Type: Print
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 71p
  • Serial:
  • Publication flags:

    Open Access (libre)

Subject/Index Terms

Filing Info

  • Accession Number: 01497550
  • Record Type: Publication
  • Report/Paper Numbers: NCHRP IDEA Project 147
  • Files: TRIS, TRB, ATRI
  • Created Date: Nov 4 2013 9:37AM