Property modification factors for seismic isolation bearings

ABSTRACT

The overall objective of this task was to develop an improved understanding of the expected performance and behavior of sliding isolationsystems;evaluate their functionality, reliability, and longevity; and assist in the development of improved codes and specifications for their use. This report deals with the problem of establishing upper and lower bound values of properties of seismic isolation bearing for use in the analysis and design of seismicallyisolated bridges. These bounding values of properties are determined by using system property modification factors. The concepts and the values presented represent the basis on which bounding analysis is described in the new 1999 "AASHTO Guide Specifications for Seismic Isolation Design"