Unique traffic loads, environmental conditions and seismic events can exert undesirable stresses on structures such as highway bridges.
One bridge in four in the Unites States is either structurally deficient or functionally obsolete. Monitoring the field performance of bridges is critical for optimizing design, maintenance and securing the long-term use.
BridgeComposites, LLC of Hornell, NY deployed a MicroStrain wireless bridge monitoring system to track the performance of seismic isolation bearings. The autonomous system continuously communicated bearing health and environmental data to engineers in real-time.
MicroStrain’s web-based data visualization and analytic tools on SensorCloud™ enabled BridgeComposites and researchers to more efficiently and cost-effectively characterize the long-term performance of bridge components.
MicroStrain’s wireless monitoring solution drastically reduced installation time compared with hardwired systems, while preserving scalable, synchronized high-speed data across any length bridge.
The network was comprised of seven wireless sensor nodes including: two G-Link® accelerometer nodes, two DVRT® linear displacement transducers, two TC-Link® temperature nodes, and an SG-Link® wireless strain gauge node.
The wireless accelerometers continuously sample vibration at 16Hz. The wireless linear displacement transducers track the longitudinal bridge movement across thermal cycles, and the wireless strain gauges monitor material deformation (and stresses) that may occur during seismic events or overloads.
Extended range synchronized sampling ensured reliable data communication. Advanced energy management protocols and energy harvesting capabilities promote multi-year operation without battery replacement.
All sensor data was wirelessly aggregated via MicroStrain’s web-enabled WSDA®-1000 gateway and transmitted to SensorCloud. On SensorCloud™ BridgeComposites viewed and shared data with the bridge owner and collaborators where they could create threshold alerts that automatically send email or text notifications when a pre-determined condition was exceeded.
According to BridgeComposites President, Jerome O’Connor, "While the system records data under an infrequent extreme event, such as an earthquake, BridgeComposites is also able to quantitatively assess continuous bearing performance remotely in real-time. Specifically, capturing the bearings behavior under traffic loading and changing environmental conditions enabled our engineers to observe response under actual service conditions."
MicroStrain’s President and CEO Steven Arms stated, “We’re excited to work with BridgeComposites to monitor the performance of next-generation bridges with seismic isolation. Our wireless sensing networks and SensorCloud provides our customers with the long term data they need to optimize structural performance and to assess structural health.”
