Your cell phone could reveal the health status of the bridges just in your pocket as you go about your daily commute.
Accelerometers and GPS sensors that are standard components on smartphones can collect data to show how bridges bend and roll as vehicles drive over them, researchers report Nov. 3 in Communications Engineering.
Collecting safety measures could keep passengers safe by alerting engineers that the bridge needs repair. The media also warn or help prevent it, as in the case of the tragic footfall in the western Indian state of Gujarat on October 30, or the span bridge that collapsed in Pittsburgh in January.SN: 11/16/07).
“This really applies to any type of bridge,” says civil engineer Thomas Matarazzo of the US Military Academy at West Point in New York. All we need, he says, is a way to get the trigger there — whether it’s in a car, in a pedestrian’s pocket or on a scooter — and some kind of monitoring device.SN: 11/10/17).
Bridge failures, Matarazzo says, often come down to questions about structural properties. “One way to reduce those uncertainties is to monitor more frequently.” Data traffic from cell phones can be the best, and perhaps the only way to receive lots of data on bridges around the world.
There are more than 600,000 bridges in the United States alone. Dedicated sensors that detect structural problems are expensive, Matarazzo says, so most bridges are inspected by eye, typically every other year.
Monitoring conditions on a bridge using simple mobile phones could make maintenance more efficient than with human inspectors alone – and much cheaper than possible with more specialized sensors. The improvement in care could save the lives of older bridges by a few years, Matarazzo and colleagues estimate, but newer bridges could last nearly 15 years longer than if they weren’t monitored in this way before being rebuilt or repaired.
To test how well cell phones could monitor bridges, Matarazzo drove over the Golden Gate Bridge on San Francisco’s 102 at times with cell phones in his car. He and his research team also collected data from Uber drivers on 72 trips over the suspension bridge. In order to check the approach of the more typical crossing bridges, which are common on the roads, the researchers arranged for the drivers to record the data for 280 crossings on a nearly 30 meter long concrete bridge in Ciampino, Italy.
For both bridges, phone sensors detected vibrations in the structures that could provide measurements within a few percent of the dedicated instruments attached to the bridges.
A single pass with a cell phone collects as much information about the bridge as a hundred or more stationary sensors, Matarazzo says. This is because phones can pass data continuously, rather than offering data from specific locations through a bridge.
If the researchers get transportation companies, government vehicle operators or the public to collaborate, the team could crunch much more information, leading to more precise measurements. Since most phones now have accelerometers and GPS, the information could be collected essentially for free.
Phones could help monitor bridges that lack sensors installed, says Huili Wang, a civil engineer at Dalian University of Technology in China, who was not involved in the study. But there are doubts about the ultimate accuracy that smartphones can provide. However, “it is a better approach without a rough estimate [adding] more sensors,’ he said.
Crowdsourced data probably won’t completely replace dedicated sensors for monitoring bridges, Matarazzo agrees. But mobile phones are useful in a few ways, he said. “The advantage is in convenience and scale. “
Bridges are a key part of transportation infrastructure. It’s important to look at the changes that can be made in days and weeks, Matarazzo says, rather than checking in over the span of a few years. “This technology allows us to do that.”
#Crowdsourced #cell #phone #data #bridges #safe #strong