The segment geometry and materials are defined according to the tunnel geometry layout.
As each tunnel is unique, so are its segment and mould.
The mould being entirely dependent on the segment geometry, its engineering can only be made according to the segment concrete design.
Therefore, the concrete design supplied by the engineering department is a crucial step within the mould developement process.
Mould engineering
A segment mould is composed of a bottom part, four side walls and two covers. The mould length can be several meters long depending on the ring size, which requires a tenth-millimetre scale adjusting accuracy.
This high precision, seldom seen in boilerworks engineering, is the main asset of CBE's know-how.
The required accuracy is especially difficult to achieve, as the side walls are made mobile to ensure the segment demoulding. In order to perform thousands of operations, the mould should be able to sustain high levels of stress and keep its
precise physical integrity during its whole life-cycle.
The mould vibration system, which is often in-built, mechanically stresses each mould component.
This stress requires systematic material strength-calculations to track down possible weak spots in the mould design.
CBE's moulds advantages
A specific design for each project
The long term experience of CBE's staff lead them to build specifically designed moulds for each tunnelling project.
The CBE Research department is in constant contact with the client during the process of segment and sealing gasket design,
in order to optimize their engineering.
The vibration and demoulding systems, the sealing gasket layout procedure, the handling systems, the materials and their components;
all the elements of the mould are specially designed for a specific tunnel project.
Any lack or blank in the CBE Engineering / Client Relationship, can lead to an un-optimized mould design,
additional costs, as well as safety problems and productivity setbacks.
CBE moulds asserts high-quality factory workCBE mould design also guarantees the segment persistence of accuracy, and reduces adjustment operations.
A mould can be used hundreds of times, up to 1500 manipulations, even more on specific projects.
Such a stressing procedure applied to a poorly designed mould would surely imply periodical adjustment
to maintain accuracy and even to some extend re-machining, and that throughout its life cycle.
Which means, as a matter of fact, additional costs and deadline overdue.
Workers' safety
Daily work at a segment manufacturing plant is repetitive and requires constant diligence,
the handling load is massive, and the project can last for months.
That's why throughout the whole mould design process, CBE aims for smoother production and improvement of the workers' safety.
The reduction of stress during handling
The machining quality of the moulds sides goes way beyond the required surface area quality for segments needed to
ease the cleaning operations, which are often tedious and lead to time and productivity loss.
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The design of a segment mould requires a lot of experience.
Our goal is to design a mould which will produce a high quality segment, able to withstand physical stress for a long period of time.
As a matter of fact, the mould will undergo strong strain.
The two main sources of strain being, on the one hand the built-in vibration system to shake concrete, and on the other hand
the numerous handlings sustained by the mould in order to produce thousands of segments needed for the tunnel.
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