Optimizing Movable and Concrete Bridge Design at STING
Challenge
STING is an engineering company that was founded in 2007 and has since then worked with a big variety of advanced bridge structures. At STING, there is a need for an analysis tool that can handle a big variety of analysis methods and features.
Solution
TECHNIA offers two different bridge analysis software. For STING BRIGADE/Plus is the better match. Its general feature-based modeling setup allows STING to model any geometry/structure that they are faced with. For each model, they can then use all the advanced analysis methods and tools that BRIGADE/Plus offer.
Results
Today, BRIGADE/Plus is the central analysis tool for STING’s engineers, that allows them to take on any type of bridge structure assignment and be sure that the functionality and tools they need is there for them to be able to deliver a complete design or analysis results.
STING is an engineering firm that was founded in 2007. Its engineers have over 30 years of experience delivering technical design solutions for advanced infrastructure in Sweden and the Nordic region. A large part of these solutions involves various types of movable bridges, such as bascule bridges and swing bridges. The complex geometries and mechanisms of these advanced structures make BRIGADE/Plus an excellent choice of analysis tool for STING. It also provides them with a tool for advanced – non-linear – investigations of both existing and new concrete bridges.
Tackling a wide range of architectural and bridge engineering challenges
At STING, they take on projects involving large movable structures, such as bridges, retractable roofs, sluices, and more. For these different projects, they deliver various services, including steel, concrete, mechanical design, hydraulics, electrical design, PLC (programmable logic controller), and SCADA (supervisory control and data acquisition) programming. For FE (finite element) calculations, BRIGADE/Plus is now a central tool at STING.
Given the wide variety of project and bridge types, the calculation tools used must be flexible. Sometimes, the projects do not involve complete system analyses but rather local investigations of parts of a structure. One such project is the movable pedestrian and cyclist bridge “Varvsbron” in Norrköping’s harbor, where stress analyses of the more complex geometries were analyzed using BRIGADE/Plus.
Nonlinear calculations for classification of concrete bridge engineering designs
At STING, the work is not limited to movable steel structures but also includes concrete bridges. One example is the Nötesund Bridge, a 614-meter-long concrete bridge that was built in 1966, making it 58 years old. As part of the maintenance work and the work on classified road sections, classification calculations are now being carried out for the bridge.
For the Nötesund Bridge, this has meant that non-linear calculations were required. It is not uncommon for non-linear calculations to be needed to demonstrate that large, complex bridges – designed according to older standards – comply with current regulations and standards.
In this instance, the columns at both approach spans were very slender, making them sensitive to second-order effects. The height of each support column also differs along the bridge, making the shorter and stiffer columns to attract more forces. With a linear analysis, the capacity couldn’t be shown to be sufficient for these columns. With a non-linear analysis, including both material and geometric non-linearity, the redistribution of forces from stiffer to slender parts of the structure could be accounted for.
In this project, the BRIGADE/Plus-specific method FBC (free body cut) was also used. The superstructure was modeled using shell elements, and to verify the model, FBC was used to extract beam section forces from the superstructure.
Free body cut tool for prestressed bridges
Another example of a large concrete structure STING has worked on is a bridge in Helsingborg across the E6 highway, for which classification calculations were carried out. The bridge is a 74-meter-long prestressed concrete bridge in three spans.
With BRIGADE/Plus, the prestressing could be implemented in the model in a simple manner. Short-term losses of the prestressing force were accounted for automatically, and long-term losses could be evaluated using viscoelastic analyses in BRIGADE/Plus.
To determine the sectional forces and moments, the extended Free Body Cut functionality in BRIGADE/Plus was used. The results were later used to verify the capacity of the bridge.
Summary
Through its versatile capabilities and advanced analysis tools, BRIGADE/Plus has become an indispensable part of STING’s engineering workflow. Whether handling complex movable bridges or ensuring the safety and longevity of aging concrete structures, the software provides the flexibility and precision required for STING to deliver innovative and reliable solutions. Want to learn more about how BRIGADE/Plus can elevate your bridge analysis projects? Contact us today to explore the possibilities!
