Bridge damage detection using probability distribution of RMSE values of moving vehicle acceleration

Abstract

In recent years, indirect bridge health monitoring methods using sensors mounted on measuring vehicles, known as drive-by methods, have received increasing attention. This study intends to investigate the feasibility of a drive-by bridge health monitoring method utilizing moving vehicle accelerations. The proposed method investigates whether there is any abnormality in the bridge by using the subtraction between the preliminary-measured vehicle acceleration when the bridge is healthy and the newly-measured vehicle acceleration when the bridge is tested. A band pass filter is applied to the vehicle accelerations before the subtraction in order to eliminate undesirable vibration components other than the frequency of the first bending mode of the bridge. The damage existence and level are investigated by calculating the RMS of the difference between the preliminary-measured and newly-measured accelerations of the vehicle. Considering the variation in the measurements, several measurements are conducted, and the RMS (Root Means Square) values and their probability distributions are examined. The laboratory experiment using a test vehicle equipped with accelerometers was conducted. Observations through this study demonstrated that the proposed method successfully determined the bridge damage existence and its level in a certain accuracy when the frequency of the first mode of the bridge varies with the damage of the bridge.