Screwed tube pile with grout injection

The screwed tube pile with grout injection is formed by screwing in permanent steel tubes vibration-free into the soil and using grout injection simultaneously. The steel tubes are welded together during the execution so as to achieve the desired installation depth.

Construction sequence

1. Implantation of the pile. Welding of the lost screw tip to seal the bottom of the steel casing equipped with an injection lance and to prevent the penetration of water and/or soil while screwing in.

2. Screwing in of the lower tubular segment and injection of the grout via an injection lance down under and around the pile base and along the pile shaft.

3. Welding of the next tubed element and injection of the grout around the pile base and along the pile shaft.

4. Reaching the desired installation depth of the pile

5. Inserting the reinforcement into the casing

6. Concreting the pile, with the possibility to maintain with great accuracy the concrete level and avoid the stripping of the pile head.

Completed screwed tube pile with grout injection

Construction chart

Fields of application

• Vibration-free pile foundation under limited height

• In confined spaces, narrow sites with difficult access and/or limited headroom applications

• In aggressive and/or contaminated soils

• Suitable in soils with strong underground flow of water, where the fresh concrete is protected by the casing

• Possibility to maintain with accuracy the concrete level, i.e. stop concreting the pile below the working level and thereby obviate the need for cutting off of the excess concrete at the cutting level

• The injection of grouting during screwing-in makes it possible to achieve higher pile bearing capacities

Environmental impact

• Vibration-free installation

• No removal of soil

• Provision should be made to remove from the working platform the excess volume of soil grout slurry generated during the injection sequence

• Low noise pollution

• A stable, dry and flat work platform is required

Technical specifications

• Full displacement of the soil

• Pile shaft diameters ranging from 168 up to 609 mm

• External diameter (or screw tip diameter) up to 720 mm

• Allowable bearing capacity up to  2.275 kN

• The pile is also known as a cased screw pile with grout injection.

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