Welcome to Retaining Walls Solutions, specialising in gravity, embedded and anchored solutions for retaining walls.
On a steeply sloping site consisting of unstable slip clay, an excavation in excess of 8.0m was required. In addition the active back face slopes significantly at nearly 20°, increasing the active side pressure.
The site investigation also documented a series of historical slip circles extending to 5.0m in conjunction with significant but sporadic water flow through the clay.
To compound the difficulty a series of TPO (tree protection orders) were issued to the site and its steeply sloping terrain prevented the use of large construction equipment and during the project a retaining wall belonging to the neighbouring property collapsed due to wind loads.
Contiguous bored pile wall, anchored into the bedrock. Above this a 3m high in-situ reinforced concrete wall was built supported off ductile iron piles and two rows of 5.0m long soil nails.
It was stabilised and retained by constructing a ring of 600mm diameter piles around the property connected by reinforced concrete beams with underpinning nibs, the beams designed to act as a box with torsion fingers as a lid to provide moment restraint to the piles, significantly increasing the factor of safety against landslide under the property.
Picture from Threefold Architects