Development and Field Investigation of a Real-Time Bridge Scour-Sensor System

Development and Field Investigation of a Real-Time Bridge Scour-Sensor System

Scour of bridge piers, abutments, and foundations has been a crucial issue in many countries, particularly Taiwan. Located in a marine tropical area, Taiwan is subject to frequent heavy rainfall and typhoons, which trigger severe flooding at river basins during the summer and fall seasons. As many old river-basin bridges experience concrete deterioration, flood-induced scour becomes a major cause of bridge damage and even collapse, resulting in substantial monetary losses and casualties each year. To address this critical issue, bridge scour monitoring and early-warning measures are urgently needed. This study developed a vibration-based sensor system and deployed the sensor system at a bridge site for field investigation. The results suggest that the developed sensor system can be used to identify the three distinct stages(i.e., the scour onset, retaining, and subsidence stages) of scour and deposition. In addition, the readings of the sensors approximately reveal the scour depth, water level, and deposition height during flooding events. Furthermore, a large-scale typhoon is associated with a large peak accelerometer amplitude and lengthy scour and deposition processes. We expect that by monitoring the scour and deposition processes of a single pier, we can understand the condition of the whole bridge.