SEISMIC RESISTANCE OF BRIDGE PIERS BASED ON DAMAGE AVOIDANCE DESIGN

Current seismic resistant design practice is based on economic (limited strength) and life safety (large displacement capacity) considerations. The seismic design philosophy that seeks to achieve these objectives is based on ductile detailing of plastic hinge regions. Unfortunately, the hysteretic energy that is dissipated in hinge zones causes damage that is generally not possible to repair. After a large earthquake, even though life-safety may have been maintained, extensive damage may have left the structure unserviceable. The research reported as part of this investigation is concerned with developing a new paradigm called Damage Avoidance Design (DAD). Construction of bridge piers is based on modular (precast) beam and column elements that are free to rock under large lateral loads. Damage is avoided by special detailing of the connections. If desired, the lateral strength can be enhanced by using supplementary unbonded prestressing tendons. Due to the use of specially detailed steel-steel interfaces, the columns are expected to behave in a bilinear fashion with neither damage nor degradation in strength and stiffness. A generalized displacement-based seismic design methodology is proposed for bridge structures with rocking piers. Damping is assessed based on the energy radiated (lost) on each impact. For a given pushover curve and effective viscous damping, the expected seismic displacement may be predicted by comparing it to the elastic design spectra (demand). To validate the proposed design philosophy, the seismic performance of a near full-size precast concrete rocking column substructure was investigated. Under large lateral (rocking) displacements, no damage to either the concrete column, connection or foundation was observed. The strength and stiffness was observed to remain the same after many cycles of loading. A complete force-deformation model for the rocking column accounting for: structural flexibility (pre-rocking), rigid body kinematics (post-rocking) and the prestressing action of the tendons is proposed. Good agreement between the predictive theory and the experimentally observed force-deformation results was demonstrated.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/10883800
• Supplemental Notes:
  • NCEER Task Number 112-D-5.1 and 5.2; FHWA Contract Number DTFH61-92-C-00112.
• Corporate Authors:

  National Center for Earthquake Engineering Research

  State University of New York, Buffalo, Red Jacket Quadrangle, Box 610025
  Buffalo, NY  United States  14261-0025
• Authors:
  • Mander, J B
  • CHENG, C-T
• Publication Date: 1997-12-10

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 142 p.
• Serial:
  • National Center for Earthquake Engineering Research
  • Publisher: National Center for Earthquake Engineering Research
  • ISSN: 1088-3800

Subject/Index Terms

• TRT Terms: Bridge piers; Columns; Dislocation (Geology); Earthquake resistant design; Earthquake resistant structures; Interfaces; Lateral supports; Loads; Precast concrete; Rocking; Steel
• Uncontrolled Terms: Damage avoidance
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00758974
• Record Type: Publication
• Report/Paper Numbers: Technical Report, NCEER-97-0014
• Files: TRIS
• Created Date: Jan 29 1999 12:00AM