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Author
Shenton, H. W., III
Title
Design Criteria for Base Isolation of Buildings.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD
Report
NIST SP 843, September 1992,
Distribution
Available from Government Printing Office
Book or Conf
U.S./Japan Natural Resources Development Program (UJNR). Wind and Seismic Effects. Joint Meeting of the U.S./Japan Cooperative Program in Natural Resources Panel on Wind and Seismic Effects, 24th. May 19-22, 1992, Tsukuba, Japan, Raufaste, N. J., Jr., Editors, 165-171 p., 1992
Keywords
building codes | design applications | base-isolation | dynamic response | relative performance | steel frame | structures | steels
Abstract
Presented are the results an investigation in which the performance of "code-designed" fixed-base and base-isolated structures were compared. Two frames, a steel concentrically braced frame and a steel special moment resisting frame were designed as both fixed-base and base-isolated in accordance with the 1991 Uniform Building Code. To establish comparable performance, the base-isolated frames were designed to varying fractions of the code recommended base shear: 100%, 50% and 25%. Non-linear time history analyses were conducted, for three ensembles of earthquakes, to assess the effect of design force level and base-fixity on response and damage level. In general, the base-isolated frames designed to 100% of the code recommended base shear out-performed the fixed-base frames. Based on average values of a number of response quantitites, comparable performance could be achieved at design forces lower than currently specified by code for the base-isolated frames.