Using Satellites To Monitor Bridge Safety

__roo writes: In an effort to detect crumbling infrastructure before it causes damage and costs lives, the European Space Agency is working with the UK's University of Nottingham to monitor the movements of large structures as they happen using satellite navigation sensors. The team uses highly sensitive satnav receivers that transmit real-time data to detect movements as small as 1 cm combined with historical Earth observation satellite data. By placing sensors at key locations on the Forth Road Bridge in Scotland, they detected stressed structural members and unexpected deformations.

Comments

Looking at a bridge from space is somehow better?

[sdguero]

This makes no sense to me. Shouldn't we be able to measure them from much closer up with much greater accuracy than 1 cm?

Re:Looking at a bridge from space is somehow bette

[Anonymous Coward]

Oh, it's pretty easy... if the bridge vanishes from the orbital image, then it is classified as "unsafe"

What does this have to do with satellites.

[niftymitch]

Other than high precision GPS what does this have to do with satellites?

Sensor technology is improving so fast that tools better than this are possible
and inexpensive. It just takes doing it. Perhaps a gaggle of folk from
the Makers Fair will do it for $101.00 next weekend.

In all fairness bureaucratic constipation costs lives.
Positive train controls should have been installed years ago on all rolling stock in the US.

Baring that a software and map update to a common sub $200 GPS that could track and log train speed
as well as sound a Klaxton to alert the engineer. It need not be integrated to the train in a
way that requires system review. Management could apply a GPS-RF transparent optionally solar powered box to
the outside of engines and other common rolling stock to record travel data. DOT could do the same
and track to see if management pressure is pushing engineers to operate outside of guidelines.

A little harder is realtime track monitoring but a shipping container bed could be modified with sensors and
a container of instrument systems mounted on it. Again there is no need to touch critical controls in ways that
risk safety for many audits. Lasers could locate surfaces on tracks with precision. G-sensors, accelerometers
acoustic audits, time, temperature are all possible. To get back to the original topic the container would
"see" track as well as bridges. Offloaded to a truck bed the container would see highways and rubber wheel
only bridges and roads. Tesla seems to have helped with the battery packaging but older Fe based power
storage would be fine as the "pig" need not be weight limited like a car.

Some of this is already happening just not enough of it. More agility is needed.

Re:What does this have to do with satellites.

[swb]

I've always wondered why city busses and other utility vehicles couldn't be mounted with sensors to measure the condition of the road surface in urban areas. You could get multiple times per day readings on many arterial streets and probably the entire city's road surface 3D scanned annually.

The data could be used for planning and organizing street patching and repair tasks at a minimum. It might also help with surfacing technology and better determine long-term major maintenance.

Bridges Are Not Static Structures!

[Irate Engineer]

The author of TFA doesn't have a clue. This idea is useless as bridges, particularly suspension bridges, deflect by much more than 1 cm under traffic and wind loads.

Here is a time lapse video of the Manhattan bridge to illustrate normal deflections:

https://www.youtube.com/watch?v=DgXveBf_l6k

Re:Bridges Are Not Static Structures!

[Irate Engineer]

Maybe, but this won't catch a lot of failures caused by corrosion or fatigue cracking, or under-designed structures that are built with excessive static deflections from the get go. Many times the first excessive deflection is the one that sends the bridge into the river. Even if this worked as advertised, it does not replace visual inspection for defects.

Look at the I-35W bridge failure in Minnesota as a case in point. Sadly, this bridge *had* been inspected visually, numerous times, and was found to be structurally deficient by design, with cracking, corrosion, and bowed gusset plates all seen and photographically recorded prior to the collapse. It was cheaper to simply schedule periodic inspections, but the inspections never triggered the required (and costly) corrections that were needed. A peak load due to construction materials and gridlocked traffic was the last straw. All the GPS and satellites in the world can't cure human stupidity.

probably good

[paul mafinga]

As long as the efforts actually pass scientific muster, as opposed to simply frightening a gullible public into ineffective tax and spend policies, it's a good idea.

That said, when an article begins with the assertion that infrastructure is crumbling, it's already biased.

Re:Looking at a bridge from space is somehow bette

[icebike]

Yes. But that would be more expensive than just installing GPS receivers on key structural components.

But you see, that is exactly what they did:

The team fixed highly sensitive satnav receivers for detecting movements as small as 1 cm at key locations on the Forth Road Bridge in Scotland.

So they just gather routine movements of the bridge, and send them electronically. If they ever start moving beyond the historical envelop they send someone to inspect. By that time the failure process is well underway.

Can it assign blame from up there?

[damn_registrars]

We've learned from other bridge collapses in the past that it is more important to place - or relieve - blame after the collapse than it is to actually do something about it. Will the satellites speed up that process as well?

Re:Receivers that transmit

[Skapare]

GPS receivers determine the position then a separate transmitter sends that position for data collection. this got called a "receiver" instead of a "monitoring device" because "GPS receivers" is a familiar term to non-techies. it's like the "DC transformers" that provide lower voltage to laptops.