Formwork Concepts for in-situ Concrete Cut-and-Cover Tunnels

Quelle/credit: Doka

279 m of cut-and-cover tunnel were constructed for the Imberg rail tunnel on the new line Wendlingen–Ulm

Quelle/credit: Doka

Cut-and-cover projects carried out by Doka (blue = slab thickness [m]; yellow = clear span [m]; red = clear height [m])

Quelle/credit: Doka

Südgürtel Graz site: example of an optimised system with only five locking levels in 12 m concreting lengths with the best utilisation of formwork complements.

Quelle/credit: Doka

The assembly of formwork elements in the workshop enables savings and ensures higher safety

Quelle/credit: Doka

Assembly of the tunnel formwork carriage at the site of the Imberg Tunnel

Quelle/credit: Doka

When striking, it is optimal first to draw the panels back on a slide in order to avoid damage to the waterstops through lowering

Quelle/credit: Doka

Electro-hydraulic lifting apparatus

Quelle/credit: Doka

Load transfer from the formwork carriage directly through the closed formwork (a) or into the lower part of the kicker (b)

Quelle/credit: Doka

Quelle/credit: Grafik nach Adolf Kleinlogel

Support reactions of a two-hinged portal frame under equally distributed loading

Quelle/credit: Grafik nach Adolf Kleinlogel

Quelle/credit: Doka

Separated support prop/V-support of formwork carriage for cut-and-cover tunnels

Quelle/credit: Doka

Percentage horizontal force and relative moment for various diagonal angles and tunnel heights

Quelle/credit: Doka

Loads on foundation

Quelle/credit: Doka

Quelle/credit: Datenquelle STUVA, Auswertung Doka

Distribution of the lengths of tunnels currently at the design phase or under construction in Germany (based on the STUVA statistics for tunnels in Germany 2014/2015)

Quelle/credit: Datenquelle STUVA, Auswertung Doka

Quelle/credit: Doka

Xface after 59 concreting pours in the wall of a tunnel formwork

Quelle/credit: Doka

Excerpt of an Xface panel from the deck area of the tunnel formwork after 59 concrete pours. Despite the many nail holes, the surface is still suitable for further concrete pours

Quelle/credit: Doka

Increasing urbanisation will lead to more than five billion people living in large cities by 2030 [1]. In addition to digital networking, it is necessary to provide mobility for these fast-growing metropolitan areas with rapid transportation routes. EU programmes for the development of the European Single Market like TEN-T include plans for the building of 58 000 km of long-distance roads, 70 000 km of railway lines and 12 000 km of national roads by 2020. As a result of this, tunnelling will play an even more significant role in the future.

In Germany, tunnel projects with a relatively constant cumulated length of about 170 km per year are to be expected. From the formwork manufacturers’ point of view these projects will be of great interest. At the turn of the year 2015/16, only 13.6 % of tunnel projects were cut-and-cover (Fig. 1), compared to mechanically bored (42.3 %) and the shotcrete method (44.0 %) [2]. The overall European potential is however considerably higher due to the construction of e.g. new underground and rapid transit lines in Paris and London, road tunnels in Norway and submerged tunnels in the Baltic.