Building a Pier on Screw Piles: Step by Step From Design to Implementation

What Has to Happen Before Design Starts

Everything downstream rests on two pieces of information. The first is what the soilis made of. A probe taken from the bank describes the bank, while the silt twelve meters out from the shore, where your piles have to find firmer ground, can be a different material. Record depth and soil layers at every planned support.

The second is size. For example In Poland, a pier up to 3 meters wide and 25 meters long in total needs only a notification to the national water authority, while anything larger goes through full permitting. Every country draws that line somewhere. Crossing it shifts your start date further than any later decision on the drawing board.

How a Pier on Screw Piles Is Designed

The forces acting on a pier pull it upward far more often than they press it down. Ice freezes onto the shaft over winter and lifts as the water rises, while the deck above weighs very little. The answer is the helix plate welded near the bottom tip of the pile: before the pile can rise, it has to drag the whole column of soil sitting above that plate.

The design has to cover five load cases:

• Pull-out from the ice gripping the shaft as water rises.

• Sideways pressure from ice, current, and moored boats.

• Weight of people and equipment on the deck.

• Bending where the deck meets the pile head.

• Scour washing the bed out around the shaft.

Bending causes the most trouble. A slender pile takes push and pull comfortably and resists bending badly, so supports are built in pairs and joined by a short cross beam. The bending then becomes one pile pressed down while its partner is pulled up, and two ordinary piles do the same for less than one oversized pile. Screw pile foundation design connects the beam and the hinged pile head.

What Installation Day Looks Like

Piles go in with light equipment, usually a mini excavator, and no groundworks are needed beforehand. A three-meter pile takes about 20 minutes with a crew of two, which means a small pier's entire foundation can be completed in one shift. Nothing is dug out, so the bed remains intact and no spoil returns to the water.

How the rig reaches each support is settled with the contractor for the particular site. Piles also never land exactly where the drawing places them, so connections have to accommodate a few centimeters of error, either through slotted holes or by drilling on site. Torque and depth are logged at every support during screw pile installation, and acceptance is built on that record.

How You Prove the Pier Will Hold

A calculation is a prediction, so a pile is loaded on site until it starts to move. Pile load testing to EN ISO 22477 pushes and pulls a test pile for about five hours, and the limit is reached when the pile has traveled 10 percent of its diameter. The curve that comes out tells the designer how much steel the ground is really asking for.

Send your site plan, depth profile, and geotechnical report to the Winkelmann Foundation Screw engineering team to get a foundation designed to address uplift at your location. Contact Winkelmann Foundation Screw for a quote.

FAQ

Are screw piles suitable for structures over water?

The method itself requires no excavation, dewatering, or concrete, so the constraint is getting the rig to each support rather than the pile's behavior. Agree on the access method with your contractor while the design is still open.

Do screw piles work in soft mud and peat?

Yes. The pile passes through the soft material until it reaches firmer ground underneath, and that depth is settled support by support. It is why pile lengths vary along one pier rather than being fixed on the drawing.

How is a pier protected against corrosion?

Hot-dip galvanized steel produced in accordance with EN 1090 is suitable for normal ground conditions. The band where the pile is alternately wet and dry wears faster than the rest, so ask what protection that section gets before you compare quotes.