Development and field evaluation of a low-cost bridge bearing movement monitoring system

Sensor-based monitoring of bridges has the potential to be an important tool to supplement visual inspection. Monitoring can provide quantitative data to evaluate the condition of bridge components (e.g. bearings and expansion joints) and to inform operation and maintenance decisions. However, the use of sensor systems to monitor bridges is often limited by cost. This paper presents the design, development, and field implementation of a low-cost micro-electromechanical systems (MEMS) and Internet of things (IoT)-based system to measure bridge bearing movement. The developed system uses accelerometers and converts changes in gravitational acceleration to longitudinal bearing displacement. The monitoring system uses a hybrid wired/wireless approach, in which the sensing nodes are wired to a gateway node from which data is transmitted to the cloud. Power is provided by means of a single battery that is charged using a solar panel. To evaluate the system performance in the field, it was installed on the Waaban Crossing in Kingston, Canada. Results of the study showed that the proposed system was capable of measuring movement of the bridge at a cost that was significantly less than a commercial monitoring system. Limitations of the system, cost of installation, and calibration of the sensors are also discussed.