FURTHER MOVEMENT of a 100-year-old clothing warehouse in east London has been prevented by Uretek UK's deep injection ground stabilisation system.
Dolta Construction is converting the four-storey building in London Lane, Hackney, into luxury flats. Consultant structural engineer for the project is Howard Cavanna.
A substantial basement runs under 70% of the L-shape building, with foundations sitting on the stable Thames Gravels. The rest of the building has shallower footings, founded on soft silt fill.
This has caused differential settlement of up to 300mm between the two sections.
One option was to demolish the building. Howard Cavanna was called in to examine ways of saving it. The firm's Peter Cavanna said the settlement did not need to be corrected, but further movement had to be prevented in the building and in an adjacent structure.
Conventional underpinning and minipiling was too intrusive and prohibitively expensive, he said. Instead, it was decided to see if Uretek's deep injection method could be used to stabilise the ground.
Tests involved multiple injections of Uretek resin up to 4m beneath the building over a 3m section. Dynamic probing before and after injection established that it would work and it was decided to treat the whole building.
Treatment was carried out on one side of the footings, which should be sufficient, although further injections from the other side may be required. Refurbishment is due to finish in the autumn.