Skewed angle

The expansion joints supplied for the construction of new bridge structures on Zurich’s northern bypass highway are special for the highly skewed crossing angle for which they required to be designed

A short drive from mageba’s headquarters, to the north of Switzerland’s biggest city, Zurich’s northern bypass motorway (part of the country’s A1 and A4 autobahns) is currently undergoing a major widening and upgrading project. Mageba is delighted to have been given the opportunity to support this project by supplying bearings and expansion joints for the reconstruction of three bridge structures at one location, where the highway and its entry and exit ramps at each side cross a railway line at a highly skewed angle. The alignment of the structures was especially significant in relation to the expansion joints at each end of each of the three crossings, which required to be designed with an unusually high skew angle of up to 37 degrees. The six expansion joints supplied, which have recently been installed, are cantilever finger joints of type TENSA®FINGER RSFD, each designed for 100 mm of movement. The joints – two with total lengths of 60 m each and four with lengths of 20 m each – were manufactured in mageba’s factory in nearby Austria.

The 22 bearings supplied for the same three structures are of type RESTON®SPHERICAL, all designed as free-sliding (accommodating sliding movements in all directions) or guided-sliding (accommodating movements along one axis only), depending on the structures’ requirements. Two of the bearings, however, required to be adaptable – initially functioning as guided-sliding bearings while two parallel structures were being constructed independently at different times, and then being combined and adapted to function as a single free-sliding bearing when the parallel superstructures were connected together.

With its own special demands, this project is typical of the challenges we face on a daily basis, forever tailoring our standard products to meet the non-standard requirements of projects all around the world – and from time to time, happily, in our own back yard.

Bridge designer: GRD c/o DSP
Contractor: ARGE Nordring Los 4 c/o Marti AG
Owner/Client: ASTRA

The three bridge structures to the north of Zurich carry a major Swiss autobahn, and entry and exit ramps at each side, over a railway line and a new road

The TENSA®FINGER cantilever finger expansion joints at each end of the three bridge structures required to be designed for skew angles of up to 37 degrees

The expansion joints were primarily fabricated in mageba’s factory in Fussach, Austria – just across the border from Switzerland

mageba supervised the installation of the expansion joints, ensuring the quality of the installation and thereby helping to ensure they will serve their purpose well for decades to come

The expansion joint at one end of the entry/exit ramp structure at one side of the main highway, following completion of installation

The superstructures of the three railway crossings are supported by RESTON®SPHERICAL bearings (one shown here in the factory), designed to accommodate structure movements as required