System identification of mid-story isolation building using both ambient and earthquake response data

Abstract

SUMMARY The behavior of story-isolated structures during an earthquake is highly affected by the characteristics of the isolation system and its location along the height of the building. Interaction between the super-structure and the sub-structure with mid-story isolation as nonlinear connector makes the mid-story isolation building even more complicated during the earthquake excitation. In this paper, two different identification techniques are applied to identify the time-varying dynamic characteristics of the mid-story isolation building using the ambient vibration test data as well as the earthquake response data. For the ambient vibration measurements, the recursive stochastic subspace identification method is used, whereas for the earthquake response data the recursive subspace identification is used. Comparison on dynamic characteristics of the story-isolated building from the results of identification is made, and the effect of nonlinear behavior of the mid-isolation system to the response of the building during the earthquake is discussed. Copyright © 2011 John Wiley & Sons, Ltd.