Glenfiddich Distillery, Dufftown, Scotland

TGS was involved with work at the historic Glenfiddich Distillery in Scotland. The 136-year-old whisky distillery sits in a valley to the north of the Speyside village of Dufftown. The large-scale project involved building an extension to facilitate further production and associated work. TGS’s involvement centred on installing a piled retaining wall.

The Project

Expanding the existing distillery required an embedded piled retaining wall next to the operational factory, so we had to detail a plan that ensured production remained on schedule. Micropiles were determined to be the best and least invasive option for the sensitive site. It was critical to position the new structure directly next to the existing building. Minipiles or larger diameter piles were both unsuitable because of the predominantly granular ground material that contained many cobbles and boulders. However, we still maintained vigilance and continually undertook vibration monitoring throughout the installation work.

The Solutions

We designed and installed the micropiles using an in-house modified method. Our drillers installed them to the design depth using rotary percussive techniques and grout flush. Reinforcement comprised full length circular hollow sections. We tied the piles at the head with a reinforced concrete capping beam before excavating the ground on the passive side to the reduced level for the new extension. Subcontractors excavated the extension quickly after we had installed the wall, as the circular hollow sections were designed to carry all of the earth pressures. Conventional concrete bored pile walls would have required a significantly longer curing time before excavation.