The article describes the use of a base isolation technique used in New Zealand allowing piers to "step" for one leg to another under the shock of an earthquake. Because of the slow stepping action, earthquake pulses are in another direction by the time a foot lifts so the pier is excited to step but not to overturn. Without stepping, an earthquake resistant design would require excessive steel. Feasibility studies showed that an energy absorber was needed to prevent the stepping action from carrying on for some time. The design of a mild steel torsion beam and lead-extrusion shock absorbers is discussed. Methods of adapting the isolators for use in buildings are mentioned. Composite lead-rubber bridge bearings could have useful applications in seismic zones. The use of a steel cantilever damper in a concrete chimney built on stepping foundations is illustrated. /TRRL/

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 24-25
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00195451
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Sep 15 1979 12:00AM