Vehicle response-based bridge damage detection is an indirect method for bridge health monitoring, in which the sensors are installed only on the travelling vehicle. However, there still exist some technical issues on the accuracy. This study suggests the estimation accuracy of the bridge mode shape as a damage index, instead of utilizing the mode shape itself. To estimate the bridge mode shapes, an interpolation matrix and singular value decomposition (SVD) are applied to extract information about mode shapes of the bridge from the vehicle acceleration responses. Validity of this method is verified through the numerical simulation and field experiment. Observations show that the proposed method provides a way to realize the damage since the change of self-correlation of bridge vibration components due to the bridge damage affects the estimation accuracy.
