Project Overview
Long Itchington Tunnel is a 320m-long reinforced concrete cut-and-cover structure forming part of the HS2 route. Constructed using a top-down methodology, the tunnel comprises three sections: the North Reception Box, the Green Tunnel and the South Porous Portal. The structure is divided into Up and Down lines by a 9.2m-high central reinforced concrete wall running through the length of the tunnel. The project required complex engineering and significant earthworks, concrete and reinforcement works to deliver this critical piece of rail infrastructure.
Scope Overview
We delivered reinforced concrete works for this cast in-situ tunnel structure using a top-down cut-and-cover construction methodology. Following the installation of diaphragm walls and roof slabs, we completed the excavation and construction of 27 reinforced concrete base slabs along the tunnel alignment. Temporary roof slab openings were incorporated to facilitate excavation, material removal and emergency access before being permanently reinstated. Working with specialist formwork provider Doka, we utilised a travelling formwork system to construct the 260m-long central dividing wall, improving productivity and delivering significant programme and cost efficiencies.
To support the South Portal construction, we delivered 88,000m3 of earthworks, placed 30,000m3 of concrete and installed 4,000 tonnes of reinforcement steel as part of this major infrastructure project on HS2.
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