Atlas screw pile

The Atlas pile is a vibration-free, cast-in-place concrete pile with double lateral soil displacement. The Atlas screw pile features virtual absence of any significant spoil and no decompression of soil around the auger tip. The lateral soil displacement and compaction effects as well as the particular helical screw shape of the concreted pile contribute to its high bearing resistance and stiff settlement behavior.

Construction sequence

1. Implantation of the pile, placement of the lost, closing nut tip under the auger head, thus preventing the penetration of water and / or soil while screwing in. Correct positioning of the unique purpose built Atlas rig, whereby the axes of both the casing and the pile are aligned.

2. By means of a combined application of rotation and vertical forces, penetration into the soil of the steel casing and the especially designed Atlas auger head is obtained (screwing-in phase).

3. Once the required installation depth is reached and if required, full-length central reinforcement is placed into the steel tube prior to concreting.

4. & 5. During the reverse screwing-out phase, the Atlas screw is withdrawn at a controlled rate and concrete is poured through the hollow stem of the auger and the concrete funnel above it. The specific helical shape of the Atlas pile is formed during the upward movement of the auger: regular pile flanges cast continuously around the pile shaft.

6. The completed screw-shaped Atlas pile – If necessary, reinforcement cages are placed manually over the upper part of the pile, after the area of the newly concreted pile has been cleaned up (not shown on the scheme).

Fields of application

• Optimal geotechnical behaviour and excellent bearing performance resulting in economical solution

• High bearing capacity thanks to the double lateral displacement of soil (during screwing-in and screwing-out phases)

• In urban environment, housing and industrial projects

• Limited transportation impact and reduced attendance cost

• Easy and quick installation

• Suitable for virtually all soil profiles and very suitable for tertiary clays

Environmental impact

• No vibration induced because the pile is formed by transmitting a combined rotation- and translation movement on the casing: important in case of vibration sensitive areas

• In noise-sensitive environment: noise production at 7 m from the machine <85 dBA (low noise level)

• Negligible extraction of (contaminated) soil – Limited or no spoil created after the completion of the piles resulting in cleaner surrounding 

• Stable, dry and flat work platform is required

Technical specifications

• Wide range of diameters: standard shaft diameters from 310 to 610 mm and screw pile diameters up to 810 mm

• Helical shaped pile shaft over the full length resulting in increased friction bearing capacity

• Atlas piles are installed to accommodate compression and tension loads.

• The reinforcement can consist of a reinforcement cage (over the full useful pile length or short head reinforcement), a central rebar, a steel profile or a combination thereof.

• Vertical or inclined piles, maximum inclination up to 1:4

• Allowable bearing capacity up to 2.300 kN in compression

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