Skanska has revealed how it has constructed an innovative ‘box within a box’ basement auditorium to shield it from the noise of nearby Crossrail and London Underground stations.
The auditorium is housed in the basement of one of four new buildings in the St Giles Circus development in London’s West End, which Skanska is constructing for client Consolidated Developments as part of a £142m contract.
Construction of the auditorium roof begins (Image: Skanska UK)
The Outernet London building within the development will feature a number of arts and culture spaces, including a 2,000-capavity underground live music venue.
Working in conjunction with Severfield, Oms Architects, Enginuiti and Buro Happold Acoustics, Skanska has had to overcome a series of technical challenges on the auditorium.
The site is close to both Tottenham Court Road Station and the Northern Line. Its foundations also straddle the Crossrail tunnel.
The ‘box within a box’ auditorium will be acoustically and structurally isolated from the rest of the basement structure, which has been achieved by building a steelwork and concrete box that sits on top of 200 acoustic packs.
Project director Paul Roberts explained how the team worked to then lift the 400t steel and concrete roof of the auditorium into its final position eight metres high using 14 separate 75t jacks. After this, 70 perimeter columns were installed underneath so the roof could be carefully released from the jacks onto the permanent columns.
Roberts said: “Since we began this project two years ago, we have faced many technical challenges, but this one is the biggest so far. The roof was only 5cm away from the surrounding structure while the jacking was taking place. These jacks are controlled by a system that is so accurate, it controls each movement to within 1mm.”
Work is expected to complete in the first quarter of 2020.
