Redevelopment of a brownfield site into a large industrial estate required a design and build slope stabilisation solution to allow excavation of the toe to accommodate building footprints. This coupled with a tight deadline in order to get the units built, open and generating revenue made for a high pressure contract.

In order to maximise the development footprint, soil nail designs had to be adapted to fit within tight boundaries. In addition, the site suffering from perched groundwater and complex hydrology, so inclined drilled drains and counterfort drains were necessary across the whole site.

Retaining walls were constructed at the toe of every slope using a combination of interlocking timber crib and pre-cast reinforced concrete units up to 4m in height. Excavation to accommodate the walls was carefully sequenced to maintain temporary stability of the slope, whilst allowing shear dowels to be installed to prevent sliding of the concrete units.

Engineered (recycled) fill material was placed behind the wall units in conjunction with granular stone to provide back of wall drainage.

Slopes above the walls were covered with MacMat R facing system and reseeded to reduce the visual impact of works after completion.

Duration:       6 months

Client:            SP Associates

Location:       Dudley, West Midlands