Modal system identification and finite element model updating of a 15-story building using earthquake and ambient vibration data

Abstract

The focus of this study is the application of novel as well as existing methods of modal system identification and finite element model updating techniques to experimental data. The data are collected during a small earthquake and from ambient vibrations. The specimen structure is named the Louis and Doris Factor Building, and is located at the UCLA campus. It was instrumented by the U.S. Geological Survey with an embedded 72-channel accelerometer network following the 1994 Northridge earthquake. This network provides continuous vibration data. The collected data were used first to estimate the modal properties of the building, which were subsequently used to update a finite element model of the structure using an improved method. The results indicate that the combined use of modal system identification and model updating techniques yields a practically useful picture of the structural state; and furthermore, this approach may be used for obtaining a calibrated mathematical model of the dynamic response of non-structural components.