Strain
Explore strain gauges designed for accurate stress and strain measurement across industrial and research applications. Shop now for solutions.
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HENT AS, a leading Norwegian contractor, undertook the development of Holmestrand Station, the world’s first station hall of its kind built inside a mountain. During the project, the client, Bane NOR, requested additional verification and long-term monitoring for the steel ceiling suspended above the tracks. The goal was to collect comprehensive performance data over the structure’s 100-year lifespan and to ensure passenger comfort by mitigating pressure changes caused by high-speed trains.
Given the unique and demanding nature of the project, HENT AS engaged HBK to deliver a specialised instrumentation solution.
Bane NOR established stringent requirements for accuracy and documentation. The steel ceiling is suspended 25 metres above the ground by six-metre rock bolts, making access and installation exceptionally challenging. HBK was tasked with instrumenting the rock anchors to continuously measure the dynamic stress on the steel support rods. The extreme environment and the unprecedented design of the station demanded a robust and highly reliable monitoring system. For HENT AS, this was their first collaboration with HBK, adding another layer of importance to the project’s success.
HBK installed measurement amplifiers from the QuantumX series, and sensors based on strain-gauge, IEPE (Integrated Electronic Piezoelectric) and piezoresistive technology. In addition to the 226 strain-gauge measurement points, three load cells were mounted on selected bolts on the steel ceiling to monitor the bolt strain over time. Three accelerometers (IEPE sensors) were also installed to enable monitoring of three-directional movement within the steel ceiling.
Other sensors installed included fifteen movement-measuring devices to detect defects and changes in movement in the rock anchors; fifteen pressure/suction sensors (piezoresistive) to monitor pressure and suction on the steel ceiling; and six sound-level meters to monitor the long-term effect of the noise-reduction measures. HBK’s catman® software was used to apply the necessary settings, log data from the sensors, retrieve values from the strain gauges and other sensors, and store all collected data. As a result, the customer has access to all required data at any time.
The installation was a resounding success, providing HENT AS and Bane NOR with confidence that the structure’s safety and quality are being continuously monitored. The effective collaboration and HBK’s expert execution have laid the foundation for a long-term partnership.
HENT AS is a nationwide total contractor in Norway, delivering all types of building projects, including total contracts, public contracts, and specialised projects within the transport sector.
HBK did an exceptional job. They were efficient, flexible and showed commitment and determination in demanding working conditions. We are particularly pleased that HBK was able to help us out at short notice and, in addition to the installation, was also able to provide expert assistance during testing. This project has been pioneering work for us, so it has been reassuring to have a supplier we could rely on to deliver quality solution.
It’s not feasible enter the ceiling space to take continuous measurements. As such, Bane NOR is clear that it wishes to continue the partnership and enter into a service agreement with HBK to carry out maintenance and calibration, even though we are not yet certain how frequently the system should be checked. In addition, we expect to receive marginal values in advance of any alarm signals being sent to Bane NOR if defects arising in the steel ceiling. This will become possible once the installation has been in operation for some time. Bane NOR is still at a very early stages of operation, and a project of this kind has never been completed before. However, speed tests have already been carried out, involving HBK staff in quality assurance tasks and the retrieval of measured data. Pressure and suction force tests have also been conducted on all of the constructions within the station hall.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, MicroStrain and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.