The West Ruislip Portal is a 438m long reinforced concrete structure that will be used to launch the two Tunnel Boring Machines (TBM’s) that will dig the twin bore tunnels for the HS2 railway in an eastward direction.
The structure is primarily comprised of three main walls, a base slab, a roof slab, a series of internal walls and a headhouse. There is also a reinforced concrete slab located behind the headwall, founded on piles & three capping beams; this will be used to site the crane that will assemble the TBM’s in the portal.
Works have included the construction of 4m high base slabs using designed scaffold access and chair support systems.
A recent concrete pour of over 1200m3 was undertaken over 2 shifts to construct the first section of the base slab for the TBM
Sian has employed over 120 operatives at peak working in 24-hour shift patterns to complete the project.
Stonebridge Road
Northfleet, Gravesend,
Kent,
DA11 9BA
