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Chanelaz Tunnel, Switzerland
Concreting in a four-day cycle
PERI tunnel formwork for variable cross-sections
An expansion of the Swiss national road network system is currently being constructed between Vaumarcus and Areuse. As part of the N5 highway, the 22 km long stretch runs through an approximate two kilometre-wide corridor between the Jura Mountains and Lake Neuenburg. Due to the various developments and activities in this region (residential areas, agricultural zones, vineyards and nature reserves), numerous civil engineering works such as galleries, tunnels and bridges are necessary.
The Chanelaz open cast tunnel, situated near Boudry, consists of a 732 m long double channel with inverted arches and includes four different cross-sections. The maximum longitudinal gradient is 3.5%. Zurich-based, Marti AG, were commissioned to carry out the concreting work and decided on the formwork concept from PERI, the leading supplier of formwork and scaffolding systems. The tunnel specialists of PERI Switzerland based in Ohringen, provided a carriage formwork solution which adapts perfectly to the varying cross-section contours.
Work began with the concreting of the eastern portal inverted arches using a steel shuttering system placed on rails. This system could be pulled forward from cycle to cycle with the help of pulleys. The carriage formwork system designed for the arched twin tunnel construction was equipped with both hydraulic and electric motors that could raise and lower the unit as well as collapse the system for shuttering purposes. According to the site foreman, Guiseppe Petrolo, “Operating the carriage was simple and allowed my formwork crew of only 4 men to complete a double section in a regular 4 day cycle.”
After concreting the first stage (see type 1 in diagram B), the carriage formwork construction was adapted to suit the following four stages (see type 2 in diagram C: standard cross-section of tunnel / tunnel with horizontal roof slabs). After re-adjusting to the arched design for the second tunnel (see types 3 + 4 in diagram D), a total of 65 stages, each comprising of 10 metre sections, were constructed in a weekly cycle.
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| Contractor: |
Marti AG, Zürich |
| Field Service: |
PERI AG Schweiz, Ohringen |
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Avdeling:
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PERI AG, Switzerland
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PERI Press Release: June 2003
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