The Earthquake Engineering Online ArchiveA response spectrum method for multiple-support seismic excitationsDer Kiureghian, Armen; Neuenhofer, Ansgar UCB/EERC-91/08, Earthquake Engineering Research Center, University of California, Berkeley, 1991-08, 66 pages (575/D37/1991) A new response spectrum method is developed for the seismic analysis of linear multidegree-of-freedom, multiply supported structures subjected to spatially varying ground motions. Variations of the ground motion due to wave passage, loss of coherency with distance, and variation of local soil conditions are considered. The method is based on fundamental principles of random vibration theory. In the proposed method, the peak response is expressed in terms of a combination rule involving the peak ground displacements and mean response spectra associated with the support degrees-of-freedom, and a set of cross-support and cross-mode correlation coefficients determined in terms of the individual spectra and the coherency function describing the nature of the spatial variability of the ground motion. A comprehensive analysis of the required cross-correlation coefficients is carried out to study the influences of the wave passage and loss of coherency effects, as well as the effect of local site conditions. The new method is applied to an example structure with three supports. Available online: http://nisee.berkeley.edu/documents/EERC/EERC-91-08.pdf (3 MB) |
