As well as achieving great height (and depths) in design and manufacturing experience in a multitude of NATM tunnelling formwork projects, Dema is proud to offer precision made segment moulds for the modern TBM method of tunnel production.
In TBM tunnelling the segments have different design types depending on the ground/soil specifications and project specifics. The shape, generally a circle, is formed by segment pieces being precisely attached together and is called a "ring". All segment patterns that make up a ring are expressed as "1 set". The segmental parts to the tunnel enable the TBM to move in different directions within the tunnel. Rings are used in different thicknesses and diameters in TBM tunnel projects. These diameter changes change the number and geometry of the precast concrete segments that make up the ring. The keystone segment is the last piece placed to complete the ring and ensures that the segment ring is stabilized. The alignment is vitally important in terms of up-down, right-left movements of the tunnel. Each segment is coded for correct sequence.
The excavations for underground tunnels for Dams, Metro, Wastewater, Drinking Water, Hydroelectric projects and irrigation projects, utilize specialized high grade concrete to provide the tunnel with strength, safety and to reduce project durations and therefore costs considerably. The TBM excavates the tunnel on the one hand, whilst behind the excavations and soil removal the individual precast concrete segments produced from the precast segment moulds are installed consecutively and are placed in the form of rings. It is due to the the segments arranged by these TBM’s that no additional support or work is required.
DEMA Formwork guarantees the durability and dimensional consistency of our segment moulds produced from our bespoke segment formwork systems. Dema Segment Moulds, the choice for dimensionally accurate precision engineered and ultimately durable moulds and for your trouble free production of concrete interlocking segment tunnel pieces.