Temeltek has in-house design capacity wiith the years of experience in in bored pile and diaphragm wall construction enabling them to produce practical and cost effective designs with alternative solutions.
As an efficient and economic method of constructing temporary or permanent retaining walls, bored cast-in-situ piles of either small or large diameter are frequently used in the construction system. These techniques are suitable for the construction of deep basements, underground structures and motorway cuttings where working space is limited or adjacent existing structures require restraint.
By utilizing the bored pile walls, excessive bulk excavations can be prevented assisting the ground movements and vibration.
There are three common bored pile wasll applications which Temeltek provides as a solution.
- Contiguous wall
- Secant wall – hard/soft or hard/firm
- Secant wall – hard/hard
Determination of the system to be utilized in the construction is provided by various factors including the type of the soil, the profile of the ground water, maximum retained heights, the duration of the construction timeline, propping requirements and cost.
Continuous flight auger (CFA) or rotary piling methods can be utilized in constructing the options.
The diameters of the pile can be constructed up to 1200mm for CFA and 3000mm for rotary methods. All options can be used with our combined guide wall system. Contiguous Wall Piles are installed at centres generally 150mm greater than their diameter therefore leaving gaps in the structural wall where soil is exposed during excavation. This option is suitable where the retained soil is usually firm to stiff (not generally granular) and where the ground water table is below the level of the maximum excavation. This is the most economic option and normally the fastest method to construct
Secant Wall – hard/soft or hard/firm
Similar to the contiguous bored pile wall but the gap between piles is filled with a unreinforced cement/bentonite mix (1 to2N/mm2) for the hard/soft wall and weak concrete (in the order of 10N/mm2) for thehard/firm wall. Construction is carried out by installing the primary piles (A) and then the secondary piles (B) are formed in reinforced concrete, cutting into the primary piles. By using this form of construction the ingress of water to any subsequent excavation can be substantially reduced.
This form of construction is generally used with the continuous flight auger process. Diameters can range from 500mm to 1200mm. Maximum depth of pile would be 29 metres with a recommended exposed height of 7 metres.
Secant Wall – hard/hard
Hard/hard wall construction procedure is very similar to a hard/firm wall but in this case the primary piles (A) are constructed in high strength concrete and may be reinforced. The Secondary piles (B) are cut into the concrete primary piles (A) using heavy duty piling rigs fitted with specially designed cutting heads. As structural concrete is used throughout there is no need to provide a lining wall. The end product provides a fully concreted face and can be an effective alternative to diaphragm wall construction. Diameters generally range from 600mm to 1200mm with a recommended depth of exposed height of 5 metres for cantilevered walls and 10 metres for a propped wall.