By D B Coomber, Keller and P W Wright, Posford and Partners
This paper was first published in GE’s July 1984 issue
Faced with a demand to provide a deeper berth at very short notice, the Port of Felixstowe found that it was necessary to strengthen an existing sheet piled quay while keeping a busy container terminal in full operation.
The solution adopted was to construct a relieving slab some 195m long and approximately 13m wide, at about 5m below ground level, supported on a large number of driven steel H-piles.
The works incorporated the largest single jet grouting contract so far carried out in the UK by GKN Keller and provided an opportunity for the technique to show its versatility by performing a number of different functions at once.
Jet grout column construction was used to support an existing crane rail foundation beam, running along the rear edge of the area to be excavated for slab construction, which had to be kept in use during construction. At the same time, the jet grout columns also served as a temporary retaining wall and ground water cut-off and were incorporated in the permanent works.
This article describes the evolution of the overall design and construction of the works with particular emphasis on the jet grouting.