As a key support element to our core services, McGee Group has significant capability in a range of piling and wall installation techniques, including; large and small diameter bored piling, continuous flight auger piling (CFA) and restricted access piling.

These techniques are used to form a variety of structures such as:

• Foundations (Bearing Piles)
• Deep Basements
• Station Boxes
• Underground Car Parks
• Bored Pile Retaining Walls
• Cut-off Walls
• Shafts

McGee Group is committed to providing a full range of services from: soft strip, asbestos removal and demolition right through to shell and core construction. By providing an in-house piling service, our clients reap the program and cost benefits of using a single contractor for all elements of the work, both below and above ground.

In addition, our in-house design service means that we are equally capable of undertaking contracts as a specialist subcontractor to the main contractor.

Techniques:

McGee Group has a range of rotary and CFA piling equipment which enables us to carry out the majority of the geotechnical works associated with any of our projects, using in-house resources.

Firstly, rotary piles are ideally suited to installing piles in stable cohesvie materials i.e. London clay. This technique is also used for installation of both king posts and plunge columns in suitable ground conditions, at diameters up to 1200mm

Alternatively, the CFA process is virtually vibration-free and one of the quietest forms of piling, making it ideal for environmentally sensitive areas. This method enables piles to be formed in water-bearing strata, without the need for casing or bentonite. It is suitable for constructing piles in most strata; gravels, sands, silts, clays and soft rocks, or even in a mixture of these as necessary and is used primarily for bearing piles and continuous/secant walls up to 900mm in diameter.

Retaining Structures - Temporary and Permanent

Bored, cast-in-situ piles of either small or large diameter are frequently used as an efficient and economic method of constructing temporary or permanent retaining walls. These techniques are suitable for the provision of deep basements, underground structures and motorway cuttings, where working space is limited or adjacent existing strucutres require restraining. This enables the avoidance of excessive bulk excavation and helps to control ground movements.

McGee Group has the capability to install both continuous flight auger(CFA) or rotary piling methods. Pile diameters can be constructed up to 900mm for CFA, and 1200mm for rotary methods.

We can construct these piles in most ground conditions, carrying their loads by friction, end-bearing or a combination of both, depending on the strata encountered.

Construction is by means of hydraulically operated, rotary bored units or crane-mounted, rotary bored units. Choice of method is dependent on factors such as; access and ground conditions.

A key advantage is that piles can be positioned close to existing structures or known underground services without imparing their stability as the piles are constructed with minimum vibration.

Depending on the strata conditions, temporary or permanent liners will be installed where ground conditions consist of non-cohesive materials or, alternatively, piles are bored under a support fluid, generally bentonite or polymer mud.

Further details on these or other piling methods employed, please contact us.