The screwed tube pile is a full-displacement pile with permanent steel casing and screw tip. The pile is formed vibration-free, by screwing steel tubes into the soil that are welded together during the execution so as to achieve the desired installation depth. The lower tubular segment is sealed at the bottom with a soil-displacing screw tip, provided with a one revolution helical blade and preventing any penetration of water and/or soil during screwing-in.
1. Positioning of the pile and welding of the lost closing nut screw tip
2. Screwing in of the lower tubular segment resulting in soil displacement
3. Welding of the next tubular element and continuation of the screwing phase. The length of the tubular segments depend on the available free working height
4. Required founding level of of the pile reached
5. Placement of the reinforcement at the required installation depth of the pile
6. Pouring of concrete, with the possibility to maintain the concrete level with great accuracy.
Completed screwed tube pile
• Vibration-free pile foundation under limited height
• In confined spaces and 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 great accuracy the concrete level, i.e. stop concreting the pile below the working level. Simply cut the steel segment, thereby avoiding the need for removing the excess concrete at the cutting level.
• Vibration-free execution
• No removal of soil
• Low noise pollution
• A stable, dry and flat work platform is required
• Full displacement of the soil
• Pile shaft diameters ranging from 219 up to 609 mm
• External diameter (or screw tip diameter) up to 720 mm
• Allowable bearing capacity up to 2.275 kN
• Inclined piles with a maximum inclination up to 1:1
• Possibility to stop concreting the pile below the working level
• Possibility to execute the screwed tube pile with grout injection
• The pile is also known as a cased screw pile