A contiguous bored pile wall is a retaining wall formed using CFA, Cased CFA (CSP), SFA or rotary bored piling techniques consisting of a row of unconnected piles cast-in-situ with a nominal gap between consecutive piles.
They are flexible in shape and design compared to diaphragm retaining walls and offer a significant lateral strength advantage compared to that of sheet piled walls.
Contiguous bored piled walls are typically installed within dry and cohesive soils, the wall is not watertight and the soil between individual piles is exposed during excavation. Reinforced mesh and spray concrete can be applied as a lining to secure the exposed soil.
A capping beam is installed to form a continuous homogeneous retaining structure that can incorporate ground anchors or temporary propping to provide additional lateral support. Depending on ground conditions walls can be installed as cantilever or a propped cantilever wall.