Data from artworks determines future design

Many bridges in the Netherlands are in need of major maintenance. But not all of them can be done at the same time. Using smart sensors and effective maintenance, "time" can be bought to keep artworks up and running as long as possible. But monitoring artworks offers much more perspective. For example, data from artworks will determine how we engineer in the future. So says Anton Gorter, project manager at Civil Engineering deBoer, known for its spectacular displacement and jacking techniques and for some time a specialist in the monitoring of structures.

Measuring and monitoring objects is a discipline that Civil Engineering deBoer has always had a knack for. "When moving or jacking objects, you want to know exactly what the displacement is, what loads are occurring and so on. We always did that with sensors," Gorter begins. "Gradually we expanded that slowly, which means that we now have an arsenal of sensors. Tools that we no longer use only for our own work, but with which we also take on separate monitoring issues."

Civil techniques deBoer distinguishes between two types of monitoring: based on electronic sensors or using fiber optic technology for the more complex issues. "With our own electronic sensors, we measure up to a frequency of 8 Hz. That does not seem like much, but is sufficient to monitor, for example, the expansion of a bridge by retrieving data once a minute," Gorter clarifies. "For the more complex issues, we work with our partner Somni Solutions, manufacturer of fiber optic sensors. With these, we are able to measure in a much higher frequency up to 1,000 Hz, or multiple measurements per second. This is extremely suitable for assessing the deflection of a joint structure, for example. In a recent setup under a bridge in Houten, we literally saw the wheel print of trucks in the measurement data. We translated that into a result and deflection in millimeters, so that calculations could be made based on this and management measures could be taken."

Civil techniques deBoer is able to provide customized monitoring based on the question. "We translate the question into the right sensors and the right measurement frequency to arrive at a good monitoring setup. After all, the goal is to retrieve the most reliable and, above all, meaningful data," Gorter emphasizes. "Moreover, our strength lies in the combination. Not only can we roll out a measurement campaign, but on the other hand we can already include remedial measures or offer an appropriate solution for this. With our standard systems, jacks and equipment, we have the ability to intervene quickly, should that become apparent from the monitoring report. For example, we can take over rejected bearings on our jacks and our measurement data provides valuable information for the design of new bearings."

Besides short-term measurement campaigns, Civil techniques deBoer also provides long-term measurements to gain insight into the health or residual life of a structure. Gorter: "For example, we have equipped the bridge over the Naardertrekvaart canal with various sensors on critical details and we monitor the behavior of the structure on a daily basis. We translate this data into useful information. By then linking limit values to this, a signal is automatically sent out if these are exceeded. This gives our client a good picture of the behavior of the structure over the longer term and a good estimate can be made for maintenance."

According to Gorter, we are only at the beginning of the possibilities when it comes to monitoring techniques. "Right now, the first steps are being taken with Artificial Intelligence, in which we can predict the future of artworks based on measured parameters. While still premature, it is a path in which steps are being taken. The same goes for the deployment of new sensor techniques to our already generous arsenal. For example, we are developing a load cell based on fiber optic technology. By placing this on a bolt head, we can continuously monitor the forces on the bolt. Ultimately, the data we generate on existing structures is crucial to the design of future structures that are expected to be equipped with sensors as standard."