HS2’s main works civils contractor in the West Midlands, Balfour Beatty VINCI (BBV), has completed the construction of the 200 metre porous portal of HS2’s Burton Green Tunnel.
The portal is the southern entrance to the 700 metre green tunnel, which will carry HS2 trains through Burton Green. Once built, the tunnel will have green space created over the top, covered with trees and plants, providing a new landscape for the local community.
Over 160 roof segments have been installed as part of the 200-metre long concrete porous portal, with each segment weighing over 20 tonnes. The porous portal features a series of vents in the roof which transition HS2 trains leaving and entering the tunnel. The pressured air wave produced by the ‘piston effect’ of the train moving through the tunnel will be channelled through the vents.
Rupert Blake, Senior Project Manager at Balfour Beatty VINCI, said: “We’re making great progress with the construction of the Burton Green Tunnel, with the south portal now complete. The next phase of construction will be the section of the tunnel to the north, where a cutting is being excavated, diaphragm walls built, a concrete roof put on, before soil is backfilled over the top ready for planting.
“A key feature is the realignment of the Kenilworth Greenway, which will follow the route of the tunnel and have large-scale planting around it. It will also provide connectivity to existing footpaths which will run across the top of the tunnel, providing green spaces for the local community to enjoy.”
To avoid unnecessary HGV movements, the soil generated by the excavation will be used as part of the wider landscaping plans in the area, sensitively integrating the railway into the local area, reconnecting wildlife habitats and enhancing biodiversity.
Once construction and landscape work is complete, the Greenway will be restored close to its original alignment, running across the top of the new tunnel, providing a link from Burton Green to Kenilworth and Berkswell for walkers, cyclists and horse-riders.
Large-scale planting of native trees and shrubs will provide biodiverse habitats for wildlife, shield the Greenway visibly from the new railway, and re-establish vegetated connections to Black Waste Wood and Little Poors Wood.