Bridge safety could receive a boost from the usage of satellite navigation sensors to monitor structural conditions.
Researchers from the UK’s University of Nottingham have teamed up with the European Space Agency to explore methods for the real time monitoring of movements in large-scale bridge structures by means of satellite navigation sensors.
The researchers chose Scotland’s Forth Road Bridge as their testing site for the new technology, given its significant increase in traffic levels over recent decades, as well as the region’s heavy winds.
Traffic levels on the Forth Road suspension bridge have risen from 30,000 vehicles per day to as many as 60,000 during peak weekdays in just the past half century.
This doubling in load levels has compromised the integrity of the bridge structure, with the appearance of sudden deformations and heavy stress on structural components.
The strong winds characteristic of the area also result in frequent closure of the bridge, which can in turn cause major traffic inconvenience and loss of revenue. As much as GBP650,000 (approximately AUD$1.272,367) in revenue is lost each day when only a single lane is open to traffic for either direction.
The researchers attached satnav receivers to critical parts of the bridge structure, in order to provide a continuous stream of measurement data to the university’s processing centre via satellite.
The satnav receivers are extremely sensitive, and capable of discerning movements within the bridge structure of as little as a single centimetre.
This highly precise data is also made accessible to users via an online website that is part of the Global Navigation Satellite System and Earth Observation for Structural Health Monitoring (GeoSHM).
The information can be used to accurately assess the structural performance of bridges, permitting managers to make more prudent safety decisions with respect to operation and closure.
“This information is extremely useful for understanding how much the bridge can move under extreme weather conditions,” said bridgemaster Barry Colford. “This allows us to decide to close the bridge based on precise deformation information.
“For example I knew that the bridge can move significantly under high winds, but the first time I know that the bridge moved 3.5 m laterlaly and 1.83 m vertically under wind speed of 41 ms.”
The data can also be combined with historic data from satellite Earth observations to ascertain the effects of environmental factors on bridge safety, such as changes to adjacent earth conditions or shifts in key structures.
While GeoSHM’s developers are currently focused on bridge monitoring, the technology can applied to any form of physical infrastructure.
“Eventually, GeoSHM could be deployed for monitoring offshore wind turbines, masts, towers, dams, viaducts, and high-rise buildings,” said Xiaolin Meng, GeoSHM team leader.
The GeoSHM technology could be prove to be particularly useful in Australia, given the sheer area of the country’s landmass and the vast geographic spread of its key infrastructure assets – especially in those remote areas where many larg-escale resource operations are situated.