Experimental investigation of the seismic response of bridge bearings.

Details

• Creators:
  LaFave, James ; Fahnestock, Larry ; Foutch, Douglas ; Steelman, Joshua ; Revell, Jessica ; Filipov, Evgueni ; Hajjar, Jerome
• Corporate Creators:
  Illinois Center for Transportation ; University of Illinois at Urbana-Champaign. Department of Civil and Environmental Engineering
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Bridge bearings
  • Seismicity
  • Earthquake resistant structures
  • Elastomers
  • Base isolation
  • Bridge design
  • Compression tests
  • Shear properties
  • Highway bridges
• Publication/ Report Number:
  FHWA-ICT-13-002
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Corporate Publisher:
  Illinois. Dept. of Transportation. Bureau of Materials and Physical Research
• Abstract:
  The Illinois Department of Transportation (IDOT) commonly uses elastomeric bearings to accommodate thermal ; deformations in bridges. These bearings also present an opportunity to achieve a structural response similar to isolation ; during seismic events. IDOT has been developing an earthquake resisting system (ERS) to leverage the displacement ; capacity available at typical bearings in order to provide seismic protection to substructures of typical bridges. The research ; program described in this report was conducted to validate and calibrate IDOT’s current implementation of design practice for ; the ERS, based on experiments conducted on typical full-size bearing specimens, as well as computational models capturing ; full bridge response. The overall final report is divided into two volumes. This first volume describes the experimental program ; and presents results and conclusions obtained from the bearing and retainer tests. The experiments described in this volume ; provide data to characterize force-displacement relationships for common bearing types used in Illinois. The testing program ; comprised approximately 60 individual tests on some 26 bearing assemblies and components (i.e., retainers). The testing ; program included (1) Type I elastomeric bearings, consisting of a steel-reinforced elastomeric block vulcanized to a thick top ; plate; (2) Type II elastomeric bearings, distinct from Type I bearings with a steel bottom plate vulcanized to the bottom of the ; elastomeric block, and a flat sliding layer with polytetrafluoroethylene (PTFE) and stainless steel mating surfaces between the ; elastomer and the superstructure; and (3) low-profile fixed bearings. Tests conducted to simulate transverse bridge motion ; also included stiffened L-shaped retainers, consistent with standard IDOT practice. Tests were conducted using monotonic ; and cyclic displacement protocols, at compression loads corresponding to a range of elastomer compression stresses from ; 200 to 800 psi. Peak displacements from initial position ranged from 7-1/2 in. to 12-1/2 in., depending on bearing size. Test ; rates were generally quasi-static, but increased velocities up to 4 in./sec were used for bearings with PTFE and for a subset ; of other elastomeric bearings. On the basis of all of the experimental findings, bearing fuse force capacities have been ; determined, and appropriate shear stiffness and friction coefficient values for seismic response have been characterized and ; bracketed.
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• Format:
  PDF
• Funding:
  UILU-ENG-2013-2-12
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27274/dot_27274_DS1.pdf
• File Type:
  [PDF - 4.90 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:15207616af05969d84875ca620ecaec0deba226a5bfa40ec3d139c07d2a6cf2c3da7c57c5f3d5be3a721b6bf62b1887dfd02f90ca6913c55b87f0dfc94e00c6d