Satellite images used to detect structures’ integrity
The European Space Agency and the University of Nottingham in the U.K. are using satellite navigation sensors to monitor bridge movements and bridge safety. Real-time sat nav measurements of the Forth Road Bridge near Edinburgh in Scotland were transmitted to a processing centre at the university. The data can indicate movements as small as 1 centimetre.
The real time satellite data was matched with historical earth measurements going back seven years to test for possible gradual changes in the surrounding ground and any movements in the structure. The project also used a web-based interface that is part of GeoSHM, the Global Navigation Satellite System and Earth Observation for Structural Health Monitoring.
It was found that the bridge moves 3.5 metres laterally and 1.3 metres vertically when the wind is blowing at 41 m/2. The applications include helping to decide when to close the bridge during bad weather.
Similar studies of a bridge in China has reportedly revealed subsidence around bridges in Shanghai and Wuhan that are caused by underground engineering and extraction of groundwater.
The GeoSHM system is designed to monitor bridges with a main span of 400 metres, but it could be used for smaller bridges, and eventually for monitoring offshore wind turbines, and high rise buildings.
To read an article by the European Space Agency, click here.