RETENTION PILING SYSTEMS

Rockend drilling has extensive experience in the design and construction of piled retention systems: Soilder piled walls, Contiguous pile walls and secant piled walls.

A piled retention system is a form of retaining wall that is used to retain the soil and in some instances inhibit the passage of water. Retention piles may also be designed to carry building loads.

SOILDER AND CONTIGUOUS PILE WALL

Soilder piling is a form of retaining wall, that provides a core system for earth retention aswell as foundation support. Soilder piles can be used as permanent walls or temporary shoring, they are best suited to ground conditions with cohesive soil/rock. Contiguous soilder piles have minimal spacing between them typically 50mm - 150mm, They are used in less favourable soil conditions in order to retain the soil behind the wall during excavation.

METHOD

Soilder pile walls are typically used in basement construction. Engineered drawings outline location, depth, spacings and diameter of piles. Holes are drilled with an auger, reinforcement cages are placed centrally within the pile and then concrete is pumped. Once the concrete has set the result is a soilder pile wall that can proceed to be tied in by a capping beam. The next process is to excavate to the desired level, lapped dowel bars are drilled into the solider piles then sprayed shotcrete walls infill between and infront the solider piles.

If the ground conditions are favourable piles maybe constructed with conventional open hole drilling, If unfavourable conditions and water tables arise CFA becomes better suited.

APPLICATIONS

• Basement construction

• Retaining walls

• Slope stabilisation

SECANT PILING

Secant piled walls are overlapped piles that create an embedded retaining wall. They are a great solution where by the piles form a continuous barrier to reduce flow of soils and water through the wall. Secant piled walls are particularly useful where ground water control is complicated.

METHOD

Secant pile walls consist on a series of piles primary piles (Unreinforced and cast in soft concrete) and secondary piles (Reinforced with high strength concrete). Initially a temporary guide wall is constructed to ensure correct pile spacing. CFA method is generally adopted for secant piling.

Primary or soft piles are the first to be installed in this sequence. Once all soft piles have been installed and set, the secondary or hard piles are installed. The hard piles are drilled in a way that they cut in and overlap the adjacent primaries.

The end result is an interlocked concrete wall that reduces flows of soils and water. The hard piles provide structural support while the soft piles resist the flow of water.

COMMON USES

• Basements and retaining wall applications where ground conditions are not favourable.

• Near shore structural support.