In September, I posted a brief about work that Applied Geomechanics (AGI) had done with the Federal Aviation Administration (FAA) to measure strain in pavement. One of the sensor types evaluated by AGI and the FAA was produced by Monitor Optics. To create this novel sensor, Monitor Optics has developed a pultrusion process that coats and protects a FBG sensor arrays so that they can be directly embedded in asphalt and concrete pavements either during construction or long after.

You can learn more about such an application on our website here. It highlights an installation in Australia that sought to quantify risks associated with potential mine subsidence under a highway. An update is here. In this case study, see how the data helped highway and mine officials identify the root cause of a road buckling event. Was it the result of thermal expansion or an indication of an imminent mine collapse? Without the data from the fiber optic sensors, the answer would not have been so clear.

Micron Optics’ FBG sensors are made for certain common applications for measurement of strain, temperature and acceleration, but the potential uses of FBG sensors go far beyond what’s covered by these products. That’s where our network of integrators steps in. One good example is Kaisen, Korea Advanced & Innovative Sensing Technology. They have developed a full line of FBG based sensors to support their civil engineering services business, and these sensors are now available for applications worldwide.

Their FBG sensors include long and short gage displacement, a double ended accelerometer, a tilt meter, several special strain gage packages for FRP and concrete applications, and a soil pressure gage. See details at http://www.kaisen.co.kr/products/FBG-sens2.htm

Fiber optic sensing has come a long way in the past decade. What were once university prototype instruments and sensors are now well qualified, commercial products. Much credit for this progress is due to a few pioneers who led the way, and one of those pioneers is Dr. Farhad Ansari of the University of Illinois at Chicago.

The Chicago Tribune recently highlighted one of Dr. Ansari’s applications. (See article) In this application, Ansari and his team installed an array of FBG scour sensors on a bridge at risk of damage from undermined foundations. If this application proves successful, these scour sensors will provide an important new tool for departments of transportation around the world. Thousands of bridges are at risk from scour, and there are few practical means for monitoring scour and its effects. For more on this scour sensor and how to access this technology, contact:

Mark P. Krivchenia
Technology Manager
University of Illinois at Chicago
Office of Technology Management
at krivchen[at]uic[dot]edu

Because these sensors are based on fiber optics, they can survive decades in this harsh environment. Also, because fiber optic sensing systems are so versatile, other FO sensors (e.g., strain, acceleration, temperature) can be added later without adding to the FO instrumentation.

Ansari’s work at UIC, as president of the International Society for Structural Helath Monitoring of Intelligent Infratructure, and as the founder of Structural Monitoring Services focuses on a central theme: advancement of measurement and analysis tools and their practical application in the field. Rather than maximizing the numbers of sensors on a structure, Dr. Ansari focuses on finding optimal numbers and types of sensors to deliver the data streams necessary — and no more. This keeps the data analysis work manageable and ensures that the structure’s owner gets actionable information.

For more on Dr. Ansari and his work, go to:

http://www.cme.uic.edu/CME/WebHome
http://ishmii.org