voussoir en béton

CONT: Jusqu'au mois de janvier, [...] cette entreprise fabriquait des moules d'acier pour voussoir en béton destinés à la fabrication de tunnels.
CONT: Les deux tunnels du TGV Atlantique auront nécessité la confection et la mise en place de 50 670 voussoirs [...]

CONT: There are a total of 17 400 concrete segments that will be used to construct the tunnel lining as the TBM [Tunnel-boring machine] progresses forward,"" ... The concrete segment consists of six individual segments 1,5 m wide, five of which each weighs 4,1 t, with a final 2-t key segment, locking the concrete segment to form a single ring unit of the concrete tunnel lining. Once the TBM has cut through the ground, we install the concrete segments and add bolts to secure the ring. The key segment also locks the ring, ... The precast segments are manufactured by Southern Pipeline Contractors at a factory located approximately 25-km east of Johannesburg.
CONT: The twin runway tunnels ... with their precast lining, required the casting and the erection of 50,670 concrete segments ...