GTL Partnership had to overcome a range of challenges when it was commissioned to provide the foundations for this year’s Serpentine Gallery Pavilion in London.
International foundation solution company GTL Partnership was commissioned to provide the foundations for this year’s Serpentine Gallery Pavilion designed by Kazuyo Sejima and Ryne Nishizawa of Japanese architect SANAA.
This is the sixth Serpentine Gallery Pavilion GTL has been involved with. For this project the firm worked closely with Arup as advisors.
Providing the foundations to a temporary structure within the complex horticultural conditions of a Royal Park has many challenges. GTL had to provide a foundation system that was sympathetic to the client’s requirement for minimal impact on land use.
The system had to be a sustainable solution which minimised spoil removal. Foundations also had to be quick to install and removed and were not allowed to leave any concrete in the ground.
GTL also had to be able to reuse the foundations on other sites after the pavilion, a temporary structure, was dismantled.
Meeting the challenge
GTL coped with the challenge by designing and installing 115 individual helical screw piles to support the columns on which the complex floating aluminium roof would be constructed.
The steel piles were designed to be screwed into the ground with minimal removal of spoil and with minimal damage to tree roots, for example. After removing the temporary structure, the helical piles can be withdrawn and reused on another project, thus providing sustainable and environmentally friendly piles.
GTL had to provide a foundation system that was sympathetic to the client’s requirement for minimal impact on land use
The piles comprise circular hollow sections onto which helical plates are welded. This allows the pile to be rotated at a constant rate of penetration into the ground with minimum disruption to the soil stratigraphy.
The pile was installed using GTL’s hydraulic power-head attached to a 10t excavator, which provided the hydraulic power and the positional alignment.
“To provide a value engineered foundation solution GTL used the cone penetration test at nine locations across the Pavilion site. This detailed soil information allowed GTL to value engineer the piles by 50% of the original design pile lengths from 4m to 2m,” says GTL technical director Tristan Toynbee. Torque was monitored throughout pile installation using GTL’s torque transducer.
A vital process
Monitoring installation torque is vital to providing a qualitative assessment of the soils and provides a second check on ground conditions. This process allows the operators to assess when the piles had penetrated the London clay formation and report anomalies to the design office. Monitoring the torque was vital to maintaining the integrity of the helical piles and eliminating damage to the pile shaft.
The torque transducer is part of GTL’s ongoing research and development programme, which includes working with Arup Geotechnics on the testing of larger diameter helical piles and exploring other potential new uses for this innovative foundation solution.
The Pavilion is the architect’s first built structure in the UK and the ninth commission in the Serpentine Gallery’s annual series of Pavilions which allows architects to debut in the UK.
Separate areas of the Pavilion contain spaces for a café and an auditorium, where the Park Nights events programme will be presented.
- The Pavilion will be open from 12 July to 18 October.