HPS (Hollow Precast Screw Pile)

The Hollow Precast Screw Pile is a ground-displacing screw pile system. The soil is displaced sideways at the tip, resulting in minimal soil uplift. When screwing the pre-stressed Hollow Precast Screw Piles, a grout mixture is injected under the lost screw point.

Application

For every foundation type, Vroom Funderingstechnieken can provide you with advice on the application of the Hollow Precast Screw Piles and which type is suitable for your project.

Features

Hollow Precast Screw Piles are highly suitable for areas with soft ground layers. Thanks to the prefab pile with KOMO certificate, there is a guaranteed shaft and no chance of concrete bleeding.
The piles are connectable, allowing work to be done under limited height.
Heat pipes can be used in the core of the pile, allowing cold/hot storage systems such as the green pole to use the piles.
The pre-stressed concrete prefab element can withstand both compressive and tensile loads.
Ground-displacing, with limited emerging drilling soil.
The ground is displaced laterally at the tip, resulting in minimal soil upheaval.
The pile system is installed without vibration and with low noise.
Hollow Precast Screw Piles can be manufactured in lengths of up to approximately 27 meters, depending on the accessibility of the foundation machine and soil conditions. The screw piles are installed using a steel guide pipe that runs through the hollow core of the pile.
When screwing the pre-stressed Hollow Precast Screw Pile, a grout mixture is injected under the lost screw point.
By screwing a prefab element with a KOMO certificate, there is a guaranteed shaft size. This makes the system highly suitable for soft soil compositions.
Production is low-vibration, which is important when production is carried out near adjacent buildings that are sensitive to settlements and/or vibrations.
The piles are hollow, resulting in savings of raw materials such as cement, sand, and gravel. The associated weight reduction also reduces transportation movements.
Stock is available for every size, allowing for quick response. In addition, elements are produced daily and are cut to the correct length for projects the day after production, as requested by the projects.

The Hollow Precast Screw Piles is hung in the mast, and through the hollow core, it is provided with a central drive shaft and a grout lance. This is connected to the cast steel screw point. The drilling torque is transmitted to the screw point by means of the drive shaft. Grout is also injected into the ground through the shaft and screw point. In this way, the foundation pile is screwed to the required pile point level. Because the piles are hollow, this offers the possibility to place hoses in them, after which the core is filled with grout and/or grout spoil. This ensures that the hoses have heat conduction to the surrounding soil. This allows for a cold/hot storage system like the green pole to be used.

Production Control

Thanks to the automatic registration of torque, pull-down force, and drilling time, the operator has real-time information about the pile being made and can immediately notice and anticipate deviations in the ground conditions: the drilling torque and insertion speed serve as an indication for monitoring the probing.

Hollow Precast Screw Piles manufactured by Vroom Funderingstechnieken can be acoustically measured and subsequently assessed by an independent advisory bureau.

Material Control

The prefab concrete elements are produced and supplied by certified producers. The grout is supplied by certified suppliers and/or central units. Certificates can be provided for these.

Vroom Funderingstechnieken manufactures Hollow Precast Screw Piles according to its own implementation procedure, which has been drawn up in the context of internal quality control and nationally applicable standards.

Get Advice

Vroom Funderingstechnieke takes the utmost care in creating our website. However, no rights can be derived from the content. If you use information from our website without verification or further advice from Vroom Funderingstechnieken, you do so at your own risk.
Vroom Funderingstechnieken accepts no liability for the accuracy and/or suitability of the information for your intended application. For questions regarding the application of our products for specific projects, we recommend contacting our sales department.

Features

Hollow Precast Screw Piles are highly suitable for areas with soft ground layers. Thanks to the prefab pile with KOMO certificate, there is a guaranteed shaft and no chance of concrete bleeding.
The piles are connectable, allowing work to be done under limited height.
Heat pipes can be used in the core of the pile, allowing cold/hot storage systems such as the green pole to use the piles.
The pre-stressed concrete prefab element can withstand both compressive and tensile loads.
Ground-displacing, with limited emerging drilling soil.
The ground is displaced laterally at the tip, resulting in minimal soil upheaval.
The pile system is installed without vibration and with low noise.
Hollow Precast Screw Piles can be manufactured in lengths of up to approximately 27 meters, depending on the accessibility of the foundation machine and soil conditions. The screw piles are installed using a steel guide pipe that runs through the hollow core of the pile.
When screwing the pre-stressed Hollow Precast Screw Pile, a grout mixture is injected under the lost screw point.
By screwing a prefab element with a KOMO certificate, there is a guaranteed shaft size. This makes the system highly suitable for soft soil compositions.
Production is low-vibration, which is important when production is carried out near adjacent buildings that are sensitive to settlements and/or vibrations.
The piles are hollow, resulting in savings of raw materials such as cement, sand, and gravel. The associated weight reduction also reduces transportation movements.
Stock is available for every size, allowing for quick response. In addition, elements are produced daily and are cut to the correct length for projects the day after production, as requested by the projects.

Production Control

Hollow Precast Screw Piles manufactured by Vroom Funderingstechnieken can be acoustically measured and subsequently assessed by an independent advisory bureau.

Material Control

The prefab concrete elements are produced and supplied by certified producers. The grout is supplied by certified suppliers and/or central units. Certificates can be provided for these.

Get Advice

Technical data

General

Slope angles on request and depending on the situation and pile length.
Available equipment: concrete pump, midigraver, auxiliary crane, grout silo, grout container, water basin.
Machine noise level approximately 90 dB. The system can be considered vibration-free.

Drilling Installation

Torque up to 200kNm.
Pull down up to 150kN.

Grout Injection

Hollow Precast Screw Piles are executed with grout injection.

Prefabricated Concrete Element

The prefabricated concrete element is hollow in the core and has a chamfer on all four sides.

Load Capacity

Ground mechanical load capacity according to Eurocode 7.

The screw point is a cast steel point adapted to ground mechanical conditions.

The load-bearing factors to be maintained according to Eurocode 7 are as follows, considering the bottom of the prefabricated concrete element as the pile point level.

Pile Point Load Bearing Factor

αp = 0.63
β= 1.0
S = 1.0

Shaft Friction Pile

αs = 0.009

Shaft Friction Tension Piles

αt = 0.009

Load and Deformation Behavior

According to Eurocode 7 (ground-displacing pile).

Load Spectrum

Depends on the diameter and soil conditions:

Up to approximately 2,500 kN compression (design value).
In specific projects, larger loads are possible in consultation with a geotechnical advisor and Vroom Funderingstechnieken.

Structural Aspects

Available shaft diameter/screw cap diameter in mm, max. length in m, max. compression load in kN:

Square shaft 260 with screw cap Ø350, 22.50m, 650kN, reinforcement in the pile core possible.
Square shaft 360 with screw cap Ø450, 27.50m, 1,450kN, reinforcement in the pile core possible.
Octagonal shaft 365 with screw cap Ø450, 30.00m, 2,000kN, head reinforcement in the element possible.
Octagonal shaft 430 with screw cap Ø550, 30.00m, 2,500kN, head reinforcement in element possible.
Larger pile lengths and/or pile loads are investigated upon request.

Manufacturing

Connect segments (only if a coupling pile is used).
Place drive shaft, also grout lance.
Connect drill point.
Vertically lift element into the foundation machine.
Clamp prefab element to pile point.
Screw in prefab screw pile.
Inject grout mixture through screw point during screwing.
If the point has reached the screwing depth, loosen the drive shaft.
Withdraw drive shaft.
If necessary, place heat/cold hoses and/or head reinforcement in the pile core, then fill with grout spoil and/or structural grout.