In the caravan, the four trucks with trailers move back and forth over the old E4 bridge in Kalix. There is full activity in the interior of the bronze, when researchers and doctoral students from Luleå University of Technology and partners keep track of sensors and measuring tools and collect data.
"We will investigate and measure the capacity of the old bridge and possible shortcomings to increase our understanding of the risks that old bridges can pose," says Gabriel Sas, professor and subject Head of Subject in Structural Engineering at the university.
With advanced equipment and dozens of sensors measurement data will be collected at the same time as heavy traffic is driven under controlled conditions in both directions of travel and then analyzed. The results will be reported in a number of scientific publications in the coming years.
"After dismantling and demolition, part of the bridge will be taken to our MCE laboratory in Luleå, where more destructive and non-destructive load tests will be performed. will be performed. We have about 30,000 bridges in Sweden, so knowledge of their service life and load capacity is crucial for both environmental benefits and economy," says Gabriel Sas.
The research group in Structural Engineering at Luleå University of Technology has extensive experience of research on bridges and their scientific publications often attract great international interest as the uncertainty regarding the capacity and safety of older bridges is global.
Gabriel Sas states that there are also great benefits to speeding up the process of examining the condition of a bridge. Instead of shutting down and redirecting traffic for days or weeks, the researchers hope that in the near future it will be possible to scan a bridge with ultrasound, radar and X-rays and inspect inaccessible parts with drones in just a few hours.
- The next step in our research is to implement the method on other bridges. Different types of bridges behave differently, says Gabriel Sas.
Researchers at Luleå University of Technology has together with the technology company TimeZYX also created a detailed digital model of the old Kalix bridge. In the future, digital copies can be a tool that makes it possible to inspect bridges at a distance, says Gabriel Sas.
In Sweden there are a number of different types of bridges; flat frame bridge is the most common while suspension bridges are quite unusual. The Öresund Bridge is an inclined cable-stayed bridge, a variant of a suspension bridge. The old Kalix bridge is a box girder bridge. The Swedish Transport Administration manages approximately 21,000 bridges, of which 17,000 are road bridges and 4,000 railway bridges.