Poursha M. An iterative process for pushover analysis of double unsymmetric-plan low- and medium-rise buildings under bi-directional excitation . IJCE 2013; 11 (2) :100-114
URL:
http://ijce.iust.ac.ir/article-1-577-en.html
Abstract: (18890 Views)
Double- unsymmetric-plan medium-rise buildings subjected to bi-directional seismic excitation are complex structures where
higher-mode effects in plan and elevation are important in estimating the seismic responses using nonlinear static or pushover
analysis. Considering two horizontal components of the ground motions makes the problem more intricate. This paper presents
a method for nonlinear static analysis of double unsymmetric-plan low- and medium-rise buildings subjected to the two horizontal
components of ground motions. To consider bi-directional seismic excitation in pushover analyses, the proposed method utilizes
an iterative process until displacements at a control node (centre of mass at the roof level) progressively reach the predefined
target displacements in both horizontal directions. In the case of medium-rise buildings, continuous implementation of modal
pushover analyses is used to take higher-mode effects into account. To illustrate the applicability and to appraise the accuracy
of the proposed method, it is applied to the 4- and 10-storey torsionally-stiff and torsionally-flexible buildings as representative
of low- and medium-rise buildings, respectively. For the purpose of comparison, modal pushover analysis (MPA) is also
implemented considering the two horizontal components of the ground motions. The results indicate that the proposed method
and the MPA procedure can compute the seismic demands of double unsymmetric-plan low- and medium-rise buildings with
reasonable accuracy however, seismic responses resulting from the proposed method deteriorate at the flexible edge of the
torsionally-flexible buildings