Nov 20 2008

Bridge Monitoring with Optical Sensors

Published by at 9:04 am under OS Technology,Sensors

One of Micron Optics’ largest market segments for optical sensing systems is for monitoring of bridges. Hundreds of bridges today are monitored using FBG based sensors, but >98% of these are in Asia and Europe. But, only a few structures in North America use this technology. Why?

I think one answer is resistance to change. Owners are more comfortable using their 35 year old visual inspection protocols than adopting better technology. And, there has been no FHWA mandate in the US that all bridges of certain classes or deteriorated condition must use objective measurements to support the visual bridge inspection process, unlike China.

An Atlanta company, LifeSpan Technologies, on behalf of our industry, is promoting the use of advanced technologies that are more precise and objective to help owners and funding agencies make better decisions. In brief, they conclude that deployment of advanced condition assessment technologies will lower both the risk and life cycle costs for bridge owners and taxpayers. I agree.

LifeSpan makes a solid case for their argument in their October 2008 white paper, A Better Way to Fix our National Bridge Problem. Find it here:

This proposed solution is independent of the assessment technology choice. And since there are number of competent technology suppliers in this business, finding what you need isn’t that difficult. Most technologies have unique features, so it pays to do your homework and compare both technical approaches and costs.

I believe that it’s only a matter of time before FHWA and the state DOTs will begin to use these advanced technologies routinely. Proposed solutions like this one from LifeSpan are sure to help accelerate the process.

Tom Graver
Director, Optical Sensing Group

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  1. Guru Prasadon 12 Jan 2009 at 6:41 am

    Yes very well said….

    But i am from India working the field of FBG for SHM.
    As of my knowledge “No Bridge or for that matter no structure in India is structurally monitored for its health”.
    In fact India has huge number of Bridges in their later age built at the time of British’s Time. All these bridges are used daily by huge number of people for their use ..this can be called as “Potential bombs” which may collapse at any time if not monitored.

    But we are as always be as Indians who will be sleeping till some disaster of great magnitude happens.On the other hand its difficult to convince people before it happens to avoid the disaster and its aftermath.

    Its a catch 22 situation where we all know something has to be done but hardly anybody is supporting….