Silkwood Park, Wakefield
Bored Pile Wall
Employing a combination of 900mm diameter king piles and 600mm diameter infill piles it creates a stiffer wall, which allows the use cost effective, more sustainable, smaller diameter piles, and achieving lower deflections.
The curved wall is much more efficient in design, as it take advantage of arching effects from the walls curvature to generate a significantly higher second moment of area, in homage to our great railway engineers of the past, but designed with modern 3D finite difference computational techniques.
By incorporating a curved wall, we were able to reduce the diameter of every second pile from 900mm to 600mm which reduced the costs of the wall and the same time saving approximately 1400 tonnes of embodied CO2 emissions associated with the production of concrete in comparison to a conventional 900mm Contiguous Wall.
In addition to the 9m cantilever wall, Foundation Piling also incorporated soil nails for retained heights less than 3m, reducing the material and embodied CO2 emission in comparison to conventional RC walls.
Our soil nail solution involved the installation of 343No nails to a depth of 3 to 6m, into weathered clays encompassing over 120m of retained soils with a layer of geogrid to allow top soil to be placed, allowing for an aesthetically pleasing vegitated finish.
As part of our drive towards a more sustainable future, we are looking at alternative non-concrete retaining wall solutions. Two of those options are gabion and reinforced soil walls.
Reinforced Soil Wall
Due to the constraints of overhead power lines, the use of piling rigs was not permitted. So a reinforced soil wall retaining 4-5m was constructed. To achieve these heights, layers of geogrid were installed with compacted clay infill was placed. The benefits of being able to reuse material cut from the piled retaining wall excavation on-site helped reduce the carbon footprint associated with hauling materials off-site whilst reducing costs and material requirements.
Due to aesthetics, the client required a solution that would provide a positive impact on the environment, whilst being able to support a new access road leading into the warehouse. For these reasons a gabion basket solution, using recycled stone was implemented. Overall 150m of gabion basket was constructed across the site.