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Section 2: Construction of foundations |
1 Card Geotechnics Limited, 44 Sandys Road, Worcester WR1 3HE, UK
2 Netlon Limited, Kelly Street, Blackburn BB2 4PJ, UK
Innovative geotechnical solutions were required to overcome the difficult logistics of construction phasing and poor ground conditions at the Royal Albert Dock Spine Road in London's Docklands. The ground conditions comprised up to 7 m of variable fill overlying soft compressible alluvium. To control settlement, a piled raft solution was designed to support the road embankment on either side of the conventionally piled Docklands Light Railway trough. The raft, comprising a granular mattressreinforced with layers of geogrid, was designed to transfer about 85% of the embankment loading onto the pile caps. This novel load transfer platform to the piled embankment produced a stable and economical foundation solution on poor ground while enabling a fast overall construction programme of 12 months to be achieved. The foundation options for the embankment and the subsequent design philosophy for the geogrid reinforced piled embankment are reviewed, together with a description of itsconstruction.