Steel Girder Bridge Case Study: Wireless Tilt (Bearing Rotation) and Wireless Strain Sensors on Steel Girder Bridge

Monitored Variables and Members: bearings rotation and strain in girders

Bridge Structure:  the steel girder bridge over the river consists 14 piers and 2 abutments. The bridge longest span is about 160 feet, and it is fracture critical.

Access Equipment used to install Wireless SenSpot sensors on bridge critical members

Installed Devices: a Resensys structural health monitoring system that was deployed on the structure consists bearing rotation (tilt) and strain SenSpot sensors. All SenSpot sensors also measure temperature in real time. SeniMax data logger with remote communication gateways were installed to collect data from SenSpot gauges and send them to main server and SenScope.

Bearing rotation (tilt) SenSpot sensor

Strain SenSpot sensor

SeniMax Gateway

Monitoring Purposes and Methods:

• Statistical analysis of strain data and comparing different girders “typical average daily variation” of stress values.
• Calculating dependence of strain and bearing rotation on temperature (temperature response rate).
• Assess functionality of the bearings’ rotation and responsiveness of pier bearings by comparing measures response rate with the expected values.
• Detect bearing malfunction