Helical Pile Foundation – O2 Walkway

Helical Pile Foundation – O2 Walkway

Portfolio Categories: Construction.

O2-Walkway-2012

Project Description

The 200-foot high walkway is suspended from two of the former Millennium Dome’s distinctive yellow masts and leads to an observation platform which allowing people to walk across. The central viewing platform provides visitors with a panoramic view of London.

It is an adrenaline based experience in which visitors get the advantage of panoramic views from the viewing platform with the experience of walking across the dome roof. It is be almost 200m (656ft) long and 60m (196ft) above the ground at its highest point, and be capable of holding up to 90 people at one time. The attraction was opened in June 2012. GTL were appointed to design, supply and install a Helical screw piled foundation solution combined with reinforced concrete blocks to support the walkway structure at both entry and exit points. Compression loads varied, peaking at 1200kN with maximum tension loads of 660kN.

Geotechnical Ground Conditions

A complex ground investigation had been undertaken in 1997 for the Greenwich Millennium Festival Site. This allowed GTL to determine the ground conditions and to derive soil parameters for their design. Saturated ground conditions were assumed conservatively within the design process.

Both compression & tension piles were designed for embedment into the River Terrace Gravels which was under laid with London Clay.

Pile Design

The O2 Roof Walk foundations combined reinforced concrete blocks supported by Helical Piles which subsequently transferred the loads into the deeper load bearing strata. The access level foundations were supported by numerous Helical piles set to depths of between 10.55m and 16.05m m.

Acknowledgements

Senior Management

Gavin Rixon – Project Director

Barnaby Tanner – Commercial Director

Karsten Richter – Lead Structural Design Engineer

Mark Stacey – Construction Manager