Estimation of Displacement Response in Steel Plate Girder Bridge Using a Single MEMS Accelerometer

Live load-induced deformation is a significant evaluation index for bridge maintenance. To measure a structural displacement response, a method using several MEMS (Micro Electro Mechanical Systems) accelerometers has previously been developed. However, this method requires several sensors, and for improved practicality, a reduction in the number of sensors is desired. Therefore, in this article, a simple displacement monitoring method is proposed that uses only one MEMS accelerometer, which is installed at the longitudinal center of the target bridge. A wavelet transform-based method is applied to the acceleration records to identify the integration range for displacement estimation. The accuracy was evaluated on an actual in-service bridge. The result indicates high accuracy of displacement measurements, with only 5% error when compared with the values recorded by a contact displacement gauge.