All advantages at a glance:
- Production-optimized design and to-the-millimeter manufacturing of segment moulds
- Turnkey segment production plants, including consultancy, planning, manufacture, assembly and commissioning
- Additional and handling equipment
- Worldwide technical service and spare parts management
- Rebuild and adaptation of used machines to new requirements
Segment production systems in operation
Each tunnel project has special tunnel lining requirements, depending on the diameter, the soil conditions and the routing, so that a safe and durable tunnel structure can be produced. Perfectly manufactured segments must be supplied just-in-time for tunnel production. After their installation in the tunnel, they have to withstand demanding use for up to 100 years. These are requirements that are very familiar for Herrenknecht Formwork, a Herrenknecht subsidiary that manufactures high-quality precision moulds and offers complete turnkey all-round solutions for the smooth production of concrete segments.
The production of segments requires to-the-millimeter precision. Important parameters like the tunnel route with its straight sections and space curves, static compliance and tunnel overburdens must be observed already when designing the rings and segments. The geometry of the entire ring and its individual segments as well as the arrangement of the joints and their sealing must be considered in the construction of moulding systems. The result is a ring design for segments that can be easily moulded and also corresponds to the high demands concerning statics and tightness.
Mould technology for forming and manufacturing
When manufacturing segment moulds and the equipment necessary for the segment production, there is no compromise in terms of precision, tolerance and resilience. During the design phase, the moulding experts from Herrenknecht Formwork have to consider not only the forces acting on the ring and the geo-mechanical stresses in the construction ground, but also the loads during production of the segments. These are, for example, ongoing vibration processes and heat requirements, taking into account the hydration while the concrete for the segments is setting.
Slab tracks for high-speed routes
Slab tracks are central elements of a stable track, a so-called “Feste Fahrbahn”. They provide for comfortable and safe traveling on high-speed rail routes, since the transitions between the precast concrete parts are perfectly aligned. The extraordinary demands on dimensional accuracy, e.g. for the “Feste Fahrbahn” system of Austrian Railway Company ÖBB and Porr AG, require high precision moulds. Long-term stress tests prove the benefits of the system and confirm the quality of the Formwork track support plate moulds.
Turnkey segment production
The just-in-time supply of segments is an important prerequisite for non-stop tunnelling operations. The Formwork experts calculate production cycles, develop optimum production concepts and set up a reliable logistics system. In addition to the segment production plants, which have a project-specific layout, Herrenknecht Formwork delivers and installs all the associated resources and equipment.
Requirements for the handling and storage of the segments, but also facilities for applying seals and the surface finish to the segments are taken into account. Service packages offer additional benefits for the segment production plant on the jobsite. Spare parts management, including professional storage, maintenance and repairs, avoids production downtimes and thus unnecessary costs.
VMT‘s modular production and logistics management System, SDS, controls, monitors and documents all major processes within the production and storage of segments and captures their position and installation data in the tunnel. SDS thus guarantees plannable, efficient, transparent handling on site and at the same time ensures compliance with quality and documentation standards combined with optimum use of resources.
Stationary or carousel production – a question of the specific project conditions
Factors such as the length of the tunnel, the planned advance rate, space conditions, manning levels and the project budget have to be considered when planning segment production. For certain conditions, stationary production is the right solution. The mould is firmly fixed to the workshop floor. Vibration dampers and adjustable bearings ensure an optimum concreting result. Carousel production, on the other hand, allows for the automated production of the segments in a production line. Due to the repetitive activities at fixed locations, the moulds are transported by drive systems to the various work stations. After demoulding, cleaning, reinforcement installation and concreting, the moulds are automatically conveyed into a heated curing tunnel. Both production methods achieve high production capacities if they are correctly adapted to the specific project requirements.
Segments in position
The segments can only be transferred to the tunnel boring machine in the tunnel if the concrete parts weighing tonnes are transported to the installation site and positioned correctly. To ensure that these steps run smoothly, different handling devices are used for demoulding and turning the segments, for attaching the seal and for storage both indoors and outdoors. It goes without saying that only lifting equipment that has been safety-tested is used.