Perth City Link, formerly known as the Northbridge Link, is a collaborative project funded by three tiers of Government and led by Metropolitan Redevelopment Authority and the...
Secant Pile Walls
Secant piled walls are embedded retaining wall structures mainly utilised to allow deep excavation in water charged ground conditions.
Using CFA – Diameters from 450mm to 1200mm.
Using Bored Piles with segmental casing- Diameters from 450mm to 1500mm.
Using Turbo Jet - Diameters from 600mm to 1200mm.
Secant piled walls are embedded retaining wall structures mainly utilised to allow deep excavation in water charged ground conditions. The walls are constructed by installing piles in a predetermined sequence. Soft (normally un-reinforced) piles are installed first followed by hard (reinforced) piles which overlap, cutting into the two soft piles on either side. Once the wall is complete the end product is a ground and water retaining wall that can also be load bearing.
This design is also suitable for retaining fine sands and very soft wet ground and may be used for cut-off walls such as cofferdams. The purpose of the secant piled wall is to ensure that the ground or composition behind the wall is securely and safely held in place despite its lateral and downward pressure against the retaining structure.
Secant pile walls can be constructed using different piling methods such as CFA, Bored Pile, Cased Secant Pile (CSP) or turbo jet (soil mixing).
- Minimal ground disturbance to adjacent property.
- Low noise and vibration.
- Excavations kept sufficiently dry that dewatering is not essential.
- Can be incorporated into permanent works to form part of the structural foundations.
- Can be used as a temporary structure.
Scope of Works
Avopiling Australia was awarded to deliver the secant pile wall of the project consisting of 174N0 900mmØ x 18.00 metres and 108No 1050mmØ x 23.00 metres deep respectively. Bored pile using segmental casing method is to be used to construct the retaining wall.