Hybrid Bridge Bents Using Post-tensioned Precast Columns for Accelerated Bridge Construction in High Seismic Regions

A new method for building seismically resilient bridges is proposed using Accelerated Bridge Construction (ABC) methods. The hybrid two-column bridge bent consists of post-tensioned precast concrete columns with a buckling restrained brace (BRB) as an external energy dissipation device. The design of initial post-tensioning forces and the selection of the appropriate strength of the BRB is provided. The BRB used had two steel cores; the first BRB steel core fractured during the 5.0% drift ratio and the second steel core fractured during the 6.0% drift ratio. The two unbonded post-tensioned (PT) bars of the west column yielded after fracture of the BRB steel cores, while the two PT bars of the east column did not yield. The precast concrete elements of the hybrid bridge bent remained undamaged up to 6.0% drift ratio. The longitudinal mild steel bars of the columns did not yield until the 6.0% drift ratio. The gusset assemblies at the cap beam and the footing remained elastic. The damaged BRB could be easily replaced after an earthquake and the steel gussets could be used to re-center the bridge bent; thus, the proposed system is promising for constructing resilient bridges using ABC methods in high seismic regions that should remain functional after an earthquake. An analytical model of a double rocking bridge bent consisting of two octagonal columns with two post-tensioned bars each and detached joints was developed using OpenSees.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 103p

Subject/Index Terms

Filing Info

  • Accession Number: 01862000
  • Record Type: Publication
  • Report/Paper Numbers: MPC-22-474
  • Contract Numbers: MPC-588
  • Files: UTC, NTL, TRIS, ATRI, USDOT
  • Created Date: Oct 21 2022 9:55AM