Applications and Techniques

Secant pile walls are an EARTH RETENTION SYSTEM used to shore up structures and excavations. They are constructed in such a way that the drilled shafts overlap each other to form a wall. In secant pile walls, the axial distance of the piles is smaller than their diameter. Key applications for secant or tangent pile walls are slope stabilisations, enable and support excavations and bulk heads as well as create barriers to groundwater flow.

 

IMPLEMENTATION

Secant pile walls are formed by constructing intersecting often reinforced concrete piles. When constructing Secant Pile Walls the primary, unreinforced piles are drilled and concreted first with secondary reinforced piles installed in between the wall of primary piles once the concrete has set in those initial shafts. The pile overlap is typically about 8 cm (or 3 inches). Using CFA piling technology, secant pile walls can be built to diameters of about 1200mm and wide range of depths.

BENEFITS

· Increased construction alignment flexibility.

· Increased wall stiffness compared to sheet piles.

· Can be installed in difficult ground conditions and offers the flexibility to fit complex site boundaries and maximising land use.

· Low noise and minimal vibrations, suitable for construction adjacent to existing buildings.
· Able to go through underground obstructions without risk of construction induced settlements to neighbouring structures.