Supporting the Serpentine Pavilion
Press Release Issued 9th June 2009-06-22
International foundation solution company GTL was commissioned to provide the foundations for this year’s Serpentine Gallery Pavilion designed by leading and highly acclaimed Japanese architects SANAA.
GTL’s expertise in this area is such that they are fast becoming the go to company for such installations; this is the sixth Serpentine Gallery Pavilion they have been involved in just four years, working with many internationally acclaimed architects. For this project they worked closely with Arup as advisors for the Pavilion. Providing the foundations to a temporary structure within the complex horticultural conditions of a Royal Park has many challenges as described below.
Working closely with Arup, GTL were asked to provide:
– a foundation system that was sympathetic to client’s requirement for minimal impact on land use;
– a sustainable foundation system that did not remove any spoil;
– a foundation system that could be quickly installed and then removed without leaving any concrete in the ground;
– a foundation system that could be extracted and reused on other sites, once the Pavilion was dismantled.
GTL were able to meet these conditions by designing and installing 115 individual helical (screw) piles to support the columns on which the complex floating aluminium roof will be constructed. The use of the GTL innovative pile system meant that the steel piles could be screwed into the ground with minimal removal of spoil and with minimal damage to tree roots, etc. After removal of the temporary structure, the helical piles could be withdrawn and reused on another project, thus providing a 100% sustainable and environmentally friendly piling system.
The pile itself consists of a circular hollow section on 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 10 ton excavator, which provided the hydraulic power and the positional alignment.
“In order to provide a value engineered foundation solution GTL used the site investigation cone penetration test (CPT) performed 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 4 m to a depth of 2 m, and shows the importance of a good SI to helical pile design,” says GTL’s Technical Director Tristan Toynbee.
Torque was monitored throughout the installation by GTL’s torque transducer; a unique and accurate system developed exclusive by GTL, far superior to existing hydraulic gauged systems available in the market, which are unreliable. The monitoring of the installation torque is vital to providing a qualitative assessment of the soils and a second check on any variability in ground conditions across the site. This process allows the operators to assess when the piles had penetrated into the London clay formation and report any anomalies to the design office. Monitoring the torque is vital to maintaining the integrity of the helical pile and eliminating any damage to the pile shaft. At present GTL is the only company of this sort to use a torque transducer to monitor torque directly applied to the pile head. 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 other potential new uses for this innovative foundation solution.
“It is always a privilege to work with internationally acclaimed architects and individuals, the fact that this is SANAA’s first built project in England is a real honour. Having been involved in many other Serpentine Gallery Pavilions we understand and appreciate that what we help construct is enjoyed by and has an influence on many people. We derive great satisfaction and pride from the fact that this remarkable London landmark, which is internationally unique, will be built on foundations designed and installed by GTL.” GTL’s Managing Director Gavin Rixon explained to New Civil Engineer.