Steel cased piles are bottom driven thin wall tubes from 1.6mm to 3.2mm thick. These are installed with mini-tracked piling rigs or with our in-house designed Mantis rig which can handle 5.0M long sections.

An internal drop hammer is used to drive a dry concrete plug at the base of the pile. Axial loads of up to 500KN can be achieved by using a combination of driving "sets" and hammer drops the pile is driven to the working load required normally with a safety factor of 2.5 or 3.0. Small diameter steel cased piles are cost effective even on very small projects due to the extreme portability of the rigs and equipment.

A larger machine is used to drive 200mm square pre-cast sections into the ground. Sections up to 6.00M long are driven to a set.

The precast pile is ideally suited to areas of loose fill or soft gravels and is quick and economic to install. Working capacities of up to 400KN can be achieved.

These piles are driven with the same rig that installs concrete pre-cast piles. However, thick wall pipe piles are particularly useful in filled gravels as they can penetrate obstructions which normally bring rotary equipment to a halt.

They are often driven open ended and then grout filled. The top section is reinforced so it can be connected to the ground beam.

Augered piles are formed using small tracked machines which use sectional flight augers normally in 1M sections to drill at the subsoil to give an open bore.

The final load capacity is dependant on the depth of the pile, the diameter of the bore and the shear strength and bearing strength of the soil. These piles are often formed with a heave sleeve in the top section to alleviate the effects of ground heave common in clay soils. A high slump sulphate resisting concrete is used with full length reinforcement.

Retaining wall construction can employ bored piling techniques - normally CFA or rotary. They provide special advantages where available working space dictates that basement excavation faces be vertical. Both methods offer technically effective and cost efficient temporary or permanent means of retaining the sides of bulk excavations even in water bearing strata.

When used in permanent works, these walls can be designed to accommodate vertical loads in addition to horizontal moments and forces.

Construction of both methods is the same as for foundation bearing piles. Continuous walls are constructed with small gaps between adjacent piles. The size of this space is determined by the nature of the soils.

A temporary casing can be screwed into the upper parts of the borehole normally to a maximum depth of 6.0M. The casing seals out any water ingress or provides support to loose soils in the first few metres of the drill hole.

As boring proceeds, the bore is lined with (temporary) steel casings screwed together in sections. These steel lining tubes are used to support unstable ground and exclude water from the bore. Where the bore has penetrated into clay it is often unnecessary to use lining tubes and the bore is advanced 'open hole'. On reaching the depth necessary to develop the required bearing capacity of the pile, a steel reinforcement cage is placed centrally in the pile.

Self-compacting concrete of high workability is then poured and at the same time, the steel lining is steadily withdrawn or can be left in situ. The method ensures that all weaknesses in the stratum are adequately filled with concrete and cover to the steel reinforcement is maintained.

We offer a full design and build package if required including piles, construction of Ground Beams and design details and drawing. We are equally happy to construct piles and ground beams to Engineer's design. We adopt a totally flexible approach.

Many riverside buildings need to be constructed above "worst case" flood levels we carry out steel frame foundations to elevate the buildings up to 1200mm above ground level.

On reinforced footing, the new construction HELICAL PIER Foundation Systems anchors are usually placed every 2.5 to 3.5 metres depending upon the load of the structure and the bearing strength of the soil.

A two man crew with a mini excavator can place over 25 anchors ready for loading in less than one day. Anchors rated by the building codes for working loads of 80 to 150 Kn are typical.
Underpinning using the underpinning support bracket is very good and high cost savings can be achieved in many situations.

Please visit http://www.abchance.com for further information.

We are approved installers for this system of piles which are particularly useful in areas where pile spoil is a problem and access is at a premium. Helical pull down micropiles are often used with our galvanised pre-fabricated conservatory "QUIK" foundation system.

For more information on patented helical pulldown piles please click the link below; http://www.abchance.com/resources/literature/01_0201.pdf

Platipus ground anchors can be used for holding back failed retaining walls, installing horizontal wick drains, anchoring Geotextiles and many diverse applications.

For further information please visit the Platipus website;
http://www.platipus-anchors.co.uk