Joint system-input identification of bridge structures

This paper presents a novel framework for system identification of bridge structures using recorded earthquake data. Bridge structures are prone to spatial variability of ground motions because they extend over relatively long distances. So, input motion measurement is a challenging task, especially for long bridges with multiple piers. Moreover, direct measurement of the bridge Foundation Input Motions (FIMs) may not be possible due to both inertial and kinematic Soil-Structure Interaction (SSI) effects. In this study, we propose a joint system-input identification solution using sparsely measured earthquake-induced responses. We verify this method and its applicability for real scale problems using simulated data obtained from the Golden Gate Bridge.