A sensor system for real-time bridge scouring monitoring

In Taiwan, many bridges have exceeded their 50-year life span. The strength of these old bridges is no longer affordable to the severe nature disasters. In other words, the bridges in Taiwan are likely to suffer from the damage. Since bridge pier scour is the main cause for bridge failure and collapse during the Typhoon in Taiwan, how to monitor the bridge scour becomes an important task. This paper presents a sensor system 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 PCBs and enclosed in a steel hollow ball and then setup in the steel cage. 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 Chih-Chang 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.