Tunnel construction: handling segments with ACIMEX devices

ACIMEX has been specialized for many years in the design and manufacturing of segment erectors and trolleys used to handle segments, through its Tunnelift range. These prefabricated arc shaped parts, weighing up to 17 tonnes each, provide the final coating for tunnels.

What is a segment?

Segments are curved prefabricated concrete or cast iron arc shaped elements, assembled by compression to form the coating of tunnels (train, subway, road, pipe, water, etc.).

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The process consists in coating the tunnels with rings of concrete consisting of 6 to 8 segments assembled together.

Generally, modern structure retaining methods are sufficient to ensure the final stability of the excavation in rocky ground. Nevertheless, some grounds change with time (swelling, mineral creep, clay consolidation, etc.). In this case, it is necessary to assemble segments to form a permanent coating for the tunnels.

In the course of the construction of the tunnel, prefabricated reinforced concrete segments 30 to 40 centimetre-thick are bolted together to form the coating. Seals are then placed between the segments of a ring and between successive rings in such a way that the process operates continuously. First objective: to achieve the strength required to resist high compression quickly.

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ACIMEX, specialist in the handling of segments with the Tunnelift range

The manufacture of segments is a significant operation which requires the creation of a large manufacturing plant and very significant handling means, given the weight and size of these bulky loads. Indeed, the weight of a single segment can vary from 3 to 17 tonnes. On site, ACIMEX Tunnelift lifters have many uses in the plant and in storage areas: standalone vacuum lifters and storage grabs are frequently used by our customers as well as stripping lifters, turners, triple clamps or tables.

Watch the video of an automated segment production  plant (copyright CONSOLIS)

To facilitate the gripping, the positioning and the installation of these segments directly in the tunnel boring machines, ACIMEX also produces customized segment erectors rotating 360°. The French brand is also specialized in the manufacture of segment trolleys equipped with hydraulic or mechanical grabs, which allow you to perform a rotation to 90° before placing the segments on a conveyor or in front of the erector.

ACIMEX, the expert in heavy handling, can work with you on your projects. Please contact us or ask us for a quote.