Recent developments are presented in an alternative to the current seismic resistant design approach for bridges and other structures based usually on flexural yielding of members designed to deform in a ductile manner. The alternative method is based on two elements; firstly, the structure is supported on flexible mountings, usually elastomeric rubber bearings, to isolate it from the predominant earthquake ground motion frequencies, and secondly, extra damping is provided to keep deflections within acceptable limits. Details of several types of practical mechanical devices developed to provide the extra damping through hysteretic energy dissipation are described. These include devices relying on cyclic flexural or torsional yielding of steel or extrusion or shear of lead. A number of applications of the devices to bridges are described including results of dynamic computer analyses of the time-history of response of the structures with and without energy dissipators, and illustrations of installation details. Results of dynamic analysis studies to investigate the sensitivity of seismic response to principal parameters for bridges incorporating energy dissipators are described and design charts to determine forces and displacement for various earthquake excitations are presented. Advantages of the approach relative to the conventional ductile design procedure are listed, in particular potential for construction economies and greater protection against earthquake induced damage. A philosophy of design of structures using the approach is proposed.(a) (TRRL)

  • Availability:
  • Supplemental Notes:
    • Seismic Design of Bridges Seminar on Bridge Design and Research, held 16, 17 and 18 November 1978.
  • Corporate Authors:

    National Roads Board, New Zealand

    P.O. Box 12-041
    Wellington,   New Zealand 
  • Authors:
    • Blakeley, RWG
    • Wennerstrand, J
  • Publication Date: 1979

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 71-145
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00323153
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0 7277 0080 4
  • Report/Paper Numbers: No 43
  • Files: ITRD, TRIS
  • Created Date: May 21 1981 12:00AM