HBM technology takes the load during bridge project

As part of a major project to restore Brazil’s longest suspension bridge, construction company Teixeira Duarte used optical and strain gauge technology, provided by HBM, to ensure the 90-year-old structure would provide safe passage for numerous pedestrians and vehicles crossing each day.

Opened in 1926 to link the Island of Santa Catarina to mainland Brazil, the Hercílio Luz bridge maintained its original structure despite sea corrosion and ever-increasing vehicle weight - loads much higher than it was originally designed to bear. Safety fears meant Hercílio Luz was completely closed in 1991, but it has since been declared a historical landmark and plans to restore the bridge put in place.

Teixeira Duarte was hired for the complete rehabilitation of the Bridge, including replacement of bearing supports in the main towers, reinforcement and recovery of foundations, plus application of new decks for vehicles and pedestrians.

The most critical part of the project involved the transfer of load from the central span of the bridge to auxiliary structures. To overcome this challenging step, Teixeira Duarte chose HBM’s technology, including sensors and optical interrogators with Fiber Bragg Grating (FBG) technology to monitor strain at critical points in the structure, electrical sensors for reading of various signals including inclination, temperature, wind and sea current.

Ricardo Martins, Teixeira Duarte’ Project Engineer explained: “The more technically complex activity is the load transfer procedure which consists of the tension relief on the eye-bars allowing their sequential replacement. The execution of this procedure implied the instrumentation of several points of the original and provisional metallic structure, with strain sensors and the application of other electric sensors as inclinometers - and climatic sensors making the total of 312 sensors. HBM presented the best offer of supply and installation, achieved through the optimized use of combined technologies; optical technology for strain measurements and data transmission to the control center, electrical for other measurements and a timely installation methodology that was required by the physical schedule of the work.”

Full details on this stage of Hercílio Luz Bridge project is available on HBM’s website: https://www.hbm.com/index.php?id=7816

Established over 65 years ago, HBM Test and Measurement is the technology and market leader, offering products and services for an extensive range of measurement applications in many industries. The company’s product range covers sensors, transducers, strain gauges, amplifiers and data acquisition systems, as well as software for structural durability investigations, tests and analysis.