DBS Civil Engineering Projects

A tight riverside plot fifty metres from the Thames, sitting on soft alluvium over London clay. We chose a secant wall so the excavation could be dug in the dry without dewatering the neighbouring wharf, then propped in two stages so the crane could keep working overhead. The thought behind the job was simple: take the water out of the argument first, and every trade behind us runs to programme.

Eleven hectares of former industrial wharf brought back into use for a logistics-led development. Rather than cart contaminated ground off site, we screened and treated the arisings on the plot and re-used them in the platform fill — a decision that kept 4,000 lorry movements off the Essex road network. The estuary edge was re-formed with a sheet piled river wall and a new haul road that becomes the estate spine.

A live high street with buses, a hotel and two schools on it — the engineering was the easy half. We sequenced the works in eight-metre bays with trench boxes and night-time reinstatement so the road opened every morning. The new 1200mm surface water run relieves a Victorian combined sewer that had flooded the basements twice in five years.

A double-fronted Victorian villa on a conservation street, taken down a full storey without a single crack in the original plaster. Hand-dug hit-and-miss pins in a 1-3-5 sequence, movement monitored daily with prisms on both party walls. The client wanted a basement that never feels like one, so the dig was set to give a 2.7m clear ceiling and a light well cut into the rear garden.

A two-level basement and podium deck carrying eleven storeys of residential above a retail plate. The transfer structure was the whole problem: column grids that suit shops do not suit flats. We ran a post-tensioned transfer slab so the frame above could land where the architect wanted it, and poured the deck in four continuous pours to keep the joints out of the waterproofing line.