DAMAGE DETECTION OF IN-SERVICE BRIDGES BASED ON THE PASSIVE TAP-SCAN METHOD

Damage detection technology is vital for bridge health assessment and management. In recent years, the bridge damage detection method using moving vehicles has attracted widespread attention because of its simple and easy operation. Specifically, the tap-scan method can improve the sensitivity of vehicle acceleration to the bridge stiffness change by applying excitation around the sensitive frequency. Since the sensitive frequency is far away from the environmental noise frequency band, a high signal-to-noise ratio can be achieved. A more portable damage detection vehicle can be designed for on-site implementation if the specific toothed wheel is applied to generate tapping force. This paper reports the field test results for two bridges in service using the passive Tap-scan vehicle. The measured data show that this method can not only detect the stiffness change ratio of the main beam but also find the support emptying. These findings verify the practicability of the passive Tap-scan method and demonstrate its engineering application value in the rapid damage detection of bridges.