Title: Earthquake Isolation of Multistory Concrete Structures

Author(s): Marc S. Caspe

Publication: Journal Proceedings

Volume: 67

Issue: 11

Appears on pages(s): 923-932

Keywords: earthquake resistant structures; frames; isolation; mathematical models; multistory buildings; optimization; reinforced concrete; shear properties; shear walls; strain rate; stress-strain relationships;structural analysis;torsion; wind pressure.

DOI: 10.14359/7324

Date: 11/1/1970

Abstract:
A new concept is introduced for the protection of multistory concrete structures from the effects of earthquake ground motions. The concept is known as an isolation technique in that the super-structure is effectively insulated from the ground vibrations. Conventional concrete frame superstructures must dissipate the energy of a major earthquake by distorting inelastically. The isolated super-structure can be made to remain elastic throughout a major earthquake because the isolation devices concentrate this energy dissipation at the base of the structure. Safety is further enhanced because the isolation devices support no part of the vertical gravity load of the superstructure. The results of tests on a mathematical model of an isolated multi-story structure are presented. Such tests show that isolation techniques can reduce the maximum base shear to a level below that causing initial yield of the superstructure, and that this shear force can be reliably established in design.