Construction start for wildlife overpass in Suhr

In the forest between Suhr and Gränichen, the Bundesamt für Strassen is building a wildlife overpass over the A1 freeway in the Rynetel area. Put simply, this is a wide, planted bridge on which animals such as the polecat, stoats, weasels, pine martens, brown hares, roe deer and wild boar will be able to cross the freeway in future. The remarkable bridge consists of two arched wooden girders, each with a span of about 17 metres. At the top, a usable width of 50 metres is available for the animals. The project is being carried out by a joint venture of Häring AG and Aarvia Bau AG. Our tasks are the production as well as the assembly of the wooden components.

The preliminary work for the construction began on 13 January 2020. This included the construction of the installation areas, access roads, etc. The concrete walls that would later support the construction were also erected. Pre-assembly could be started in mid-August. With the help of a surveyor, the exact points for the steel parts were measured and then precisely moved. After all the steel parts had been placed in one direction of travel, we were able to start assembling the trusses during the nights of 24 and 25 August. For this purpose, the roadway in the direction of Zurich was completely closed from 9.30 p.m. to 4 a.m.. The portal for the entrance and exit areas of the tunnel was completely prefabricated and hoisted into place on site with a mobile crane. The portal is 18 metres long and 4 metres wide and weighs about 10 tonnes! A second work crew simultaneously placed and assembled individual arch trusses with a length of 17 metres. The rest of the work will continue until about the end of September.