A real-time bridge scour sensor system with accelerometers

Many bridge structures are facing the nature disasters such as earthquakes and floods due to the fast global climate change. Since bridges are the important pivots of traffic and the damage of bridges can cause the severe cost of human life and property. These nature disasters cause lots of bridge collapse or destruction and thus endanger our daily life. Bridge scour is the main cause for bridge failure and collapse during the Typhoon in Taiwan, thus how to monitor the bridge scour becomes an important task. This paper presents a sensor system with our proposed algorithm to detect the bridge scour in real time. The presented sensor system consists of under-water sensor nodes with the wired Ethernet communication protocol, a PoE switch and a data logger. The proposed under-water sensor node is implemented with two-stacked octagon PCB and enclosed in a steel hollow ball and then setup in the steel cage. The volume of the steel hollow ball with the octagon PCB design can achieve the large reduction compared with that using traditional rectangle PCB design, thus reduces the cost of underwater sensor nodes. Our developed under-water sensor node adopts the vibration sensing mechanism to detect the bridge scour by using the accelerometer sensor. The presented sensor system is now setup in Min-Chu Bridge in the middle of Taiwan to monitor the bridge scour. The experimental results in the field during the Typhoon Dujuan show the presented sensor system can detect the bridge scour effectively with our proposed scour detection algorithm in real time.