Strasbourg train station, FR
Getting from Strasbourg to Paris in less than two and a half hours is made possible by the new TGV connection. In order to adapt Strasbourg Central Station to this peak performance, the entire station forecourt was redesigned. Since November 2007, the historic entrance building has been protected by a glass porch, which was built under the premises of transparency and filigree.
Project data
Architect
Jean-Marie Duthilleul (AREP), Paris
Client
French Railways, SNCF
Structural engineering
Engineering office RFR, Paris
Façade planning and execution
Engineering office RFR, Paris
Glass supplier
Schollglas Technik GmbH Objektzentrum, Heynitz-Lehden
Historic and modern architecture hand in hand
The Strasbourg railway station was built between 1878 and 1883 according to the designs of the architect Johann Eduard Jacobsthal. At the request of the client, the French railway SNCF, this historic building was to retain its presence despite the expansion. This task resulted in a glass building of complex geometry that pushes in front of or over the old building in a gentle curve and creates a covered connection between the train station and underground car park as well as the tram, bus and taxi transport systems. The transparent design of the filigree steel structure continues to guarantee an unobstructed view of the former entrance building while at the same time providing a high quality of stay in the interior. The glass porch with a length of 120 metres and a height of 25 metres is composed exclusively of curved individual elements. The primary supporting structure consists of a total of 16 main arches spanned by stainless steel cables, which rest on pendulum supports at a distance of 9 metres. Horizontal bracing is provided by a secondary structure – stabilisation elements under tension rods at intervals of 4.50 metres – as well as a tertiary structure that is also curved. Seele GmbH from Gersthofen, a specialist in complex steel-glass constructions, has prepared exact calculations in order to apply the necessary forces to the various tensile elements and thus ensure the balance of the construction.
Resistant glass with special requirements
The glass shell of the stem is formed from curved individual panes in four different radii. For the transparent shell, Schollglas supplied around 13,000 m of glass in sizes ranging from 808 mm x 1332 mm to 4478 mm x 1699 mm. Two different types of laminated safety glass were used: The first composite consists of single-pane safety glass GEWE-dur-H® made of K-Glass™. The hot-bearing, thermally toughened safety glass GEWE-dur-H® is characterized by a permanent stress distribution in the glass and thus ensures high resistance to mechanical and thermal stresses. The second type of laminated safety glass was assembled from GEWE-tvg® panes and also has a K-Glass™ pane in the composite. GEWE-tvg® is particularly suitable for use in overhead areas due to its good residual load-bearing behaviour. Due to its one-sided pyrolytic coating with metal oxide, K-Glass™ is chemically and mechanically very resistant and neutral in view and transparency.
Sun protection for visitors to the Nahmhof
In order to ensure sun protection, the outer pane of the laminated safety glass units in the upper part of the building was provided with a 2-colour screen print: This was applied on level 2 – and thus on the side that was later laminated. The arrangement of the printing gives the glasses a white exterior and a black interior effect. It was a particular challenge for SCHOLLGLAS to position the dot curve from 5 mm to 19 mm in diameter so precisely that the dots are congruent. In addition, a sun protection film in the PVB laminate and the K-Glass™ on the inside ensure that the glass construction does not heat up too much in sunlight.
The complex steel-glass construction had to meet other requirements: There could be no connection between the old and the new building, as the historic building had to remain not only visible, but also untouched for reasons of monument protection. Another requirement was: earthquake safety. This makes the new glass porch an engineering masterpiece and at the same time an architectural gem and does credit to the new TGV connection with top speeds of 320 kilometres per hour.
