Following the partial collapse of Carola Bridge in Dresden, Germany last week, research has revealed early indicators of the structure’s instability.
The bridge’s collapse occurred on 11 September when a 100m long section gave way into the River Elbe.
The research was conducted via a satellite-based risk assessment from insurtech firm Value.Space. Insurtech utilises technologies such as artificial intelligence, big data analytics, blockchain, and machine learning, to support the insurance industry.
Value.Space confirmed it had conducted a satellite-based assessment of the Carola Bridge from 14 September 2021 to 4 September 2024 prior to last week’s collapse.
Its findings revealed there were significant indicators present prior to the incident to suggest inspection/consultation with on-site engineers would have been necessary.
They also uncovered “A distinct movement cluster on the western superstructure of the bridge of up to 23.50 mm per year,” Value.Space said. Additionally they showed that from October 2022, the movements in the cluster began to show an atypical pattern with diverging paths
Additional movement on the northern side of the bridge structure was also revealed, which could have indicated additional stress accumulation in the bridge’s western superstructure
The Carola Bridge’s connects Dresden’s historic old town to other parts of the city, one of four bridges crossing the Elbe River.
According to a spokesperson from Dresden’s Road and Civil Engineering Office, the bridge was frequently inspected and the section that collapsed was scheduled to undergo renovation next year. The entire bridge was last renovated in 1996.
Information on Dresden City Council’s website said that demolition and clearance work following the partial collapse of the Carola Bridge was progressing after the incident.
During the night of September 13 to 14, emergency services dismantled and removed further parts of the bridge. Last weekend, the demolition work on the bridgehead on the Neustadt side was scheduled so that equipment and technology could be removed in view of the rising Elbe water level.
The Federal Agency for Technical Relief (THW) continues to support the demolition work on site with monitoring, securing and lighting. The German Armed Forces were also on site with two recovery vehicles. Test drilling was also being carried out on the Carola Bridge to investigate the cause of the collapse.
Since the incident, Germany’s environmental agency has been in contact with the State Office for the Environment, Agriculture and Geology, the State Dam Administration and the Technical University, Institute of Hydraulic Engineering and Water Management in Nuremberg.
According to estimates, the water level of the Elbe in Dresden will not be significantly affected by the debris from the collapse. The flow conditions in the water and the flow velocities will change in the area of the weir formed by the bridge parts after the Carola Bridge. By the time it reaches the Marien Bridge, however, the flow of the Elbe will have returned to the normal flow pattern.
It was also determined that bridge elements in the water, would raise the water level by around 30 to 50cm from the Carola Bridge to the level of the Waldschlösschen Bridge about 4.5km west of the Carola Bridge.
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Bridge collapse carola bridge dresden 2024-09-17