The Earthquake Engineering Online Archive

A new floor response spectrum method for seismic analysis of multiply supported secondary systems

Asfura, Alejandro; Der Kiureghian, Armen

UCB/EERC-84/04, Earthquake Engineering Research Center, University of California, Berkeley, 1984-06, 108 pages (530/A823/1984)

This study presents an improved floor-spectrum method for seismic analysis of linear, MDOF secondary systems multiply supported on linear, MDOR primary systems. The method defines and uses an extension of the conventional floor response spectrum, i.e. cross-cross floor spectrum (CCFS). Through this extended concept, important effects which are not accounted for in current floor-spectrum methods are correctly included in the analysis. The proposed method consists of two basic steps: (1) generation of CCFS in terms of the ground response spectrum and the modal properties of the primary system and (2) determination of the mean peak response of the secondary system by modal combination in terms of the CCFS. Several representative primary-secondary systems are numerically analyzed. Results obtained using the proposed method are compared with results obtained by considering the primary-secondary system as a single structure.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-84-04.pdf (4 MB)