Retaining Walls

Secant Piled Wall

Alternate soft piles are formed using either a slow-gain concrete or a workable grout mix. The installation sequence is determined by ground conditions, but is normally on a hit and miss 2 or 3 piles basis. After a sufficient initial curing period (2-4 days) and once each alternate pile is formed, the reinforced ‘male’ piles are installed. The male and female piles overlap by approximately 75-100mm. The secant between hard and soft piles ensures that water seepage is minimised and fines wash-out is prevented. The interlocking secant wall is not watertight; however water flow is greatly reduced. Similar pile sizes and retained heights to contiguous piling can be offered.

Secant Pilled Wall

Contiguous Piled Wall

Piles are installed, in a sequence determined by boring conditions. The wall is not watertight and measures may be required to prevent fines wash-out between the piles. Each pile is reinforced with a cage, designed to resist bending moments and shear. Pile diameters of 350-1200mm are offered, retaining up to 15m.

Contiguous Piled Wall

King Post Walls

Piles are bored and concreted using standard piling equipment however rather than a standard reinforcement cage, a Universal Column section is inserted into the pile shaft. Piles are placed at 2-3m centres. As the excavation proceeds, in-fill planks are placed in the web of the UC sections, supporting the dig. The in-fill panels are typically timber sleepers, pre-cast concrete planks, second-hand steel sheet piles or trench sheets. The web has to be cleared of concrete as the excavation proceeds. Concrete adhesion can be reduced by bitumen coating the UC prior to insertion.

King Post Wall