The soils on the Chelsea Flower Show project were a mix of alluvial deposits and clays, all overlain by 3m of fill (top soil, rubble etc).
The design prediction for the pile length was 16.5m and, in reality, the piles achieved required torque at depths between 12m and 16m.
The pile size used was the P28 2.875″ 8,10,12 helices with modified new-construction top bracket (see photo below).
MacLean Civil Products group (MCP) helical piles can rapidly provide reliable and economical structural support to new or modular buildings and structures, even in confined and awkward spaces. They are ideal in situations where speed, vibration, noise, contaminated ground or soil removal are concerns or where there is restricted access. As a proprietary, modular system, MCP helical piles are simple to specify, easy to handle and transport, and they can be installed with hand-held equipment. Once a temporary structure is removed, these helical piles can be extracted easily from the ground by simply being ‘unscrewed,’ leaving the land in good condition.
Working with our United Kingdom distributor, MCP supplied 12 helical piles to award-winning James Basson’s M&G Garden. The impressive display featured nearly 150 different plants across several families. M&G Garden was awarded Best Show Garden at the 2017 Chelsea Flower Show, for which our distributor supplied some unseen, but critical, components. The garden, which featured monumental blocks of limestone of varying sizes and two large stone clad steel towers, at 8m and 5m high, required temporary foundation support.
The Royal Horticultural Society does not allow any major excavations to be carried out and all means of structural support used for the show were required to be removed once the show was over. Tree roots and other obstructions had to be avoided when installing foundation elements for the garden design. The ideal solution, overcoming all these potential problems, was provided by our distributor, using MacLean’s technically innovative proprietary system certified by the International Code Council (ICC).
The main garden contractor contacted the distributor that supplied 12 MCP, 2-7/8″ round shaft piles (model P28 with 8″-10″-12″ helices), which were rapidly installed by their approved installer. The circular, hollow section pipe piles were simply turned vertically into the ground using a hydraulic drive head at the specified spacing and calculated torque. This installation required no excavations or soil removal.
The helical lead section was installed first and followed by extension sections until they reached the load bearing strata. Each installed pile was then fitted with an engineered flat top plate bracket. The stone tower exhibits were supported on a steel frame spanning between the piles. The steel frame was connected directly to the pile heads above ground via a Lindapter clamp arrangement (see photo below). This offers an ideal connection for temporary or modular buildings, as no concrete is required, making the installation very quick and eco-friendly.
Once the show was complete, the stone columns were dismantled and the reliable and economical MCP piles were just as easily extracted from the ground by simply being turned out of the ground.
MCP is proud to work with its distributor on numerous specialized projects throughout the UK. The MCP anchor team is always striving to build solid foundations worldwide in various projects of diverse nature.
M&G Garden at the Chelsea Flower Show
Lindapter (Top) and Chelsea Flower Show pile installation (Bottom)