Ladycross Shaft, Woodsmith
UK

Woodsmith Mine is a proposed polyhalite fertiliser mine being developed in the Northeast of England by Anglo American. A 37km long tunnel is being constructed by Strabag UK through which polyhalite will be moved, via conveyor, to the mineral handling facility on Teeside. The tunnel contract is valued at over £1B and includes two intermediate ventilation and access shafts to depths of up to 360m.

Geo-Design were appointed to design and supervise a grouted environmental cut off for the Ladycross Shaft, located inside the North Yorkshire Moors National Park, with challenging geological and hydrogeological conditions and sensitive receptors nearby. The grout cut off was achieved using an innovative application of colloidal silica, an inert mineral grout:

• Grouting design
  Detailed design of innovative colloidal silica grouting scheme.
• Site supervision
  Design, and site supervision of the design implementation in addition to verification of the grouted cut off from site monitoring and hydrogeological modelling.
• Construction support
  Retained during construction of the upper section of the shaft to advise on encountered ground conditions.