University Develops Bridge Construction Technology


Last month, structural engineers at Vienna University of Technology—also known as TU Wien—premiered the success of its bridge construction technology during a two-bridge project on the Fürstenfeld Motorway in the Austrian Alps.

Described as an unfolding approach or umbrella method, the technique was applied by ASFINAG.

About the Technology

According to TU Wien, the technology was patented in 2006 and first applied in 2010, but has since been refined and tuned for large scale projects.

To break down how the technology works: a bridge is balanced vertically verses the traditional horizontal practice by erecting two girders straight up and down alongside a concrete pier; then, using hydraulic systems, the joint is rotated downward into place, like an umbrella.

Once the thin-walled prefabricated elements that are reinforced with steel and essentially hollow are successfully lowered, crews then fill them with concrete.

“Erecting bridges using scaffolding usually takes months,” method developer Johann Kollegger said in a statement. “The elements for the balanced lowering method, on the other hand, can be set up in two to three days, and the lowering process takes around three hours.”

However, Kollegger adds that the technology isn’t well-suited for less invasive for bridges through protected or uneven terrain but has shown to save time, money and might even prove to be more durable than traditionally constructed bridges.

“Now that we have proven that the method is well-engineered and works perfectly,” says Kollegger, “we hope that it will prevail and will soon become one of the common bridge building methods that are used around the globe and that the S7 Motorway will become an international pioneer.”

Research for the project was supported by the Austrian Research Agency, the Association of Austrian Concrete and Precast Plants, ASFINAG Bau Management GmbH and ÖBB Infrastruktur AG.

The Project

Erected over several phases, the Lahnbach bridge crossing was assembled between October 2019 and January, while the larger bridge over the Lafnitz took place on Feb. 27.

The rotated girders of both bridges weighed 54 tons and were 36 meters (roughly 105 feet) in length, totaling a 72-meter-long span post lowering. Following the lowering process, the abutments were spanned using suspended girders, making the Lahnbach Bridge 100 meters long and the Lafnitz Bridge 116 meters long.

The university adds that for both bridges, four lowering processes were conducted side by side in order to create the required width for the motorway.

Other parties involved with the project outside of ASFINAG and Kollegger included planner Schimetta Consult ZT GmbH; inspecting engineer Öhlinger + Partner Ziviltechniker GmbH; construction supervisor Spirk + Partner; construction company Kostmann GmbH; prefabricators Franz Oberndorfer GmbH & Co KG; and post-tensioning, lowering technologists KB Vorspann-Technik GmbH.


Tagged categories: Bridges; Bridges; Colleges and Universities; EU; Europe; Infrastructure; Infrastructure; Program/Project Management; Research and development; Technology

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