Smartphones Could Help Tell If Bridges Are In Need Of Repairs

Researchers at MIT have come up with a new study showing that smartphones, when placed in vehicles and equipped with special software, could help reveal the structural integrity of bridges while driving across them, a potentially cost-effective way of alerting authorities when a bridge needs repair. 

Trialing the research on the Golden Gate Bridge, the team found that ordinary mobile devices containing accelerometers could capture the same information from the bridge’s vibrations as stationary sensors commonly attached to them. 

The scientists compared the findings from the smartphones to the data recorded by the bridge’s sensors, noticing that both sets of data converged on 10 particular types of low-frequency vibrations. At the same time, in five cases, there was no discrepancy between the two methods. 

However, only 1% of the bridges in the United States are suspension bridges, the more common form being concrete span bridges, which make up 41% of the nation’s structures. To test if the smartphones would work as well on such bridges, the team tested the method on another bridge in Ciampino, Italy. 

Comparing 280 vehicle trips to the six sensors placed on the structure, the researchers found a 2.3% divergence between the two methods, and a 5.5% divergence over a smaller sample. While the results were still encouraging, this could mean a larger sample size would be needed for more accurate data. 

Going forward, the scientists plan to refine and expand the ongoing research, including how to account for the vibrations of the smartphone mount in vehicles, if the type of vehicle influences readings, and more. 

Despite the method still being in its early stages, it certainly could prove to be a less costly alternative to bridge sensors in the future, with the team suggesting mobile-device monitoring could even add 15% to 30% more years to the expected lifespan of a bridge. 

“We still have work to do, but we believe that our approach could be scaled up easily—all the way to the level of an entire country,” explained Carlo Ratti, Director of the MIT Sensable City Laboratory. 

“It might not reach the accuracy that one can get using fixed sensors installed on a bridge, but it could become a very interesting early-warning system. Small anomalies could then suggest when to carry out further analyses,” he added.

[via New Scientist and MIT News, cover image via Lunamarina | Dreamstime.com]