Observed dynamic performance of the Yokohama-Bay Bridge from system identification using seismic records

Abstract

Strong motion data acquired from instrumented bridges during seismic events provides an excellent opportunity to gain insight into the behaviour of bridges and performance of their components. Using system identification, modal parameters of bridges can be estimated and the performance during various level of earthquake can be studied. In this study dynamic behaviour of Yokohama-Bay Bridge is investigated using seismic response recorded from six earthquakes. Modal parameters of the structure are estimated using system realization of state–space model. The realization method used here is based on the system realization using information matrix (SRIM), which makes use of the correlations between earthquake input and output data to identify the coefficient matrices of state–space model. Identification results from six earthquakes show that the system identification can be used to capture global behaviour of the bridge by estimating modal parameters and also to explain local behaviour of its component such as performance of link-bearing connections during earthquake. Copyright © 2005 John Wiley & Sons, Ltd.