Overview

Keller was contracted by Glencar Construction Ltd to provide a combination of both rigid inclusions and CFA solutions for the construction of a new HQ for a specialist wood manufacturer, comprising a 163,000 sq ft, 52m clear span warehouse on a brownfield docklands site for the Mersey Dock & Harbour Co Ltd. 

Challenge

Keller was to provide a foundation solution through up to 17m of very low-strength tidal blat deposits whilst limiting settlement to <25mm and 1:500. Having originally designed this warehouse on piles, Keller was asked to offer an alternative that would accelerate the build and cut carbon.  It was also asked to provide support to a heavily loaded crane base area which was positioned immediately next to an existing dock wall and through some very coarse backfill. 

Solution

Keller offered a combination of RIs and CFA piling for this scheme. The RIs were installed to facilitate shallow foundations (200kN/m2) and a ground-bearing floor slab (53kN/m2). For the crane base, 450 and 600mm diameter CFA piles were adopted to limit load shed and penetrate to depth. Keller was also able to switch between the RI and CFA tools using the same rigs, which avoided additional mobilisation costs.

Outcome

The works were completed swiftly, with the substructure activities following on immediately behind. This enabled Glencar Construction Ltd to accelerate its programme.