Last week, the condition of the “Tankinkbrug”, a bridge in the Hof van Twente township, is investigated using a range of technologies, including drone-based inspection. Determining the condition of a bridge can avoid situations as occurred last year at the Merwede bridge near Gorinchem, by predicting the actual state of the bridge accurately. “Rijkswaterstaat”, researchers from the University of Twente and a number of SMEs from the Twente region are involved in this fieldlab from Twente47
A lot of bridges and viaducts in the Netherlands have (nearly) reached the end of their expected theoretical end of life. This does not imply that these must be replaced immediately. However, current inspection models offer only limited information, which hampers an accurate assessment of the actual condition and remaining useful (safe) life of the assets. Improving the insight in the current status and identifying the changes allows asset owners to better estimate when maintenance of replacement is necessary.
The pilots that took place on July 10th and 11th, are complementary to the research pogram “Kunstwerken in Control” (Assets in Control), financed by Rijkswaterstaat and the province of Overijssel. Methods are developed in the program to gain insight in the problem when to replace large assets such as bridges and viaducts. The tests are executed by a the University of Twente, Saxion University of Applied Sciencs, Inertia Technology, DRONExpert, Antea Group, Strukton, Contractor Pelle.
Development of warning systems
One of the pilots executed at the Tankinkbrug focuses on the development of a warning system based on camera images and Artificial Intelligence (AI). Camera images are made by drones, as well as by static cameras on the shore. De images are converted to a 3D image of the bridge. Damage can be identified and categorised automatically from these images, using AI. Insight in the technical remaining (safe) life of the asset is obtained by following the state images over time.
Digital copy as instrument for monitoring
The second pilot aims at developing a “digital twin”, using sensors on the bridge. Monitoring the behaviour of a bridge with sensor is, by itself, not innovative. However, the use of a digital twin, to assess the current state of the bridge and simulate future developments of the state of the asset is innovative. This aims at providing asset owners with the necessary information to decide and plan maintenance or replacement actions. The behaviour of the bridges is measured with accelerometers and displacement sensors, but also with high resolution cameras.
Both types of monitoring will be used in a complementary way. The digital twin is very useful during the construction of an asset and the first months of operation, as well as near the end of the expected technical end of life of the asset. The warning system is useful in the period between the initial and end phase of the bridge’s life.