Screw Piles – Benefits of AB CHANCE® Helical Screw Piles
• High capacity piles with small compact equipment • Safe to use around trees and roots • No spoils removed during piling
• Every pile is tested during installation using torque correlation method invented by AB CHANCE over 70 years ago.
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AB CHANCE® helical solid steel shaft screw piles can be used in a variety of sectors
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Inexpensive and straightforward to install.
- Available in a range of sizes and dimensions
- Screwed straight into the ground making them the ideal choice instead of concrete foundations.
- Reusable
- Removable
- Low level of noise produced
- No concrete is necessary – reducing time and costs
- Cost-effective
- A conventional piece of equipment such as the mini excavator or the track excavator is used to install these piles
- Use a low-speed high-torque hydraulic motor at an appropriate speed. This is an inexpensive and fast way to mobilise.
- No need to use a crane or a large drilled shaft rig. All that is typically needed is one labourer and one operator.
- Can operate in restricted access and be carried through a standard door opening and used as a hand-held rig,
- Ease of Installation of Piles
HPM Micropile Install
Why Use AB CHANCE?
No deep trenches required
Excavating deep trenches in the ground can be a risky and time-consuming job unless you use piles.
For example, if you have trees within 10 metres of your property and the ground conditions are clay, you should consider screw based foundations as your engineer and building control are likely to require you to dig between 2.5 to 3 metres deep for traditional foundations.
Helical screw piles can be loaded immediately
This option is unique in that they can be loaded straight after installation.
There is no need to wait for grout to harden.
This is ideal for projects such as emergency response where the construction schedule is extremely short and the remainder of the project relies on the readiness of the screw piles.
Helical screw piles cause minimal disturbance
Helical anchors typically do not generate soil cuttings, resulting in minimal site cleaning required after each installation. This directly leads to a reduction in project costs. Furthermore, the associated noise level is low, unlike many other construction sites.
Since there are no soil cuttings, there is no need to handle any contaminated soils. This serves as a significant environmental advantage, ensuring a welcome benefit for the environment.
The process
The process is simple: Apply torque to the shaft to place the screw pile into the soil. The helical shape of the bearing plates generates a pulling force, propelling the helical screw pile forward. The helical system screws into the ground with minimal soil disturbance, distinguishing it from an augur.
Once the lead section penetrates the soil, attach a lead extension plate to the solid square shaft.
Progress continues until reaching the desired bearing capacity of the pile.
Throughout the installation, measure the capacity continuously using the torque correlation method, as the torque applied to the shaft indicates the pile’s capacity.
True composite micropile
The innovative AB CHANCE® screw piles have the option to also function as both an end bearing and a friction pile resulting in a true composite micropile. This is achieved by a grout column (cement and water) being pulled down with the pile by use of a displacement plate attachment for increased bearing capacity (skin friction). This means fewer piles on your installation and ultimate protection in all soil conditions.
Attachments
The AB CHANCE helical screw piles come with a number of attachments to terminate the pile. For example, new construction brackets for apartment blocks, bridges, houses or walkway construction, underpinning brackets for the lifting of existing buildings in cases of cracks and subsidence, tie back or retaining wall soil screw attachments.
AB CHANCE helical screw piles are constructed of a solid steel square shaft and galvanised for added protection.
Helical screw piles and ease of access to remote sites
Screw/ helical anchors are most suited for projects that are located in a remote area where any mobilisation costs would be particularly high and support services are low in supply. Unfortunately, with some project sites, congestion causes issues with engineers and any projects that involve performing with limited head space also adds to any concern. As these foundations are fabricated consisting of extensions and lead sections, they are perfect for any situations where low or limited access is needed.
Helical screw piles are ideal for soft ground
These foundations typically do not need an excavation when installing. If however they are being used to underpin an existing structure a shallow one is used to expose existing foundations. The use of these piles will help eliminate the need for any pumps and will also reduce costs.
Helical screw piles can be installed at all angles
Typically they are installed vertically but in fact, they can be installed at any angle to suit the requirements of the project. Installing on a batter will provide additional resistance if needed. It is that simple.
Very versatile system
As they are specifically designed to be used within grounds where there may be varying application requirements (such as various lengths and thicknesses) they are a highly versatile option which is utilised across a plethora of applications, including new builds, house extensions, transport and communications.
This method of construction offers the following advantages:
- Faster construction
- No excavation spoils to remove
- Can be installed in any weather and tree-friendly
- Permits building on weak soil conditions
- No heavy equipment required, restricted access handheld installation
- Installs in limited access situations
- May be installed close to tree roots or existing foundations
- Can be used to underpin foundations to stop subsidence
- High capacity applications up to 1000kn
Ability to increase load capacity
Our piles possess a unique feature, allowing them to enhance the load capacity through the modification of screw/helical elements’ configuration. Choosing this option offers several green benefits:
- The piles are designed to be installed and left in place for multiple years, facilitating reuse by others.
- The utilization of high-quality steel not only conserves energy but also contributes to an overall reduction in the carbon footprint.
This is why many engineers consider this their number one choice.
Ground Sun screw piles installations
AB CHANCE Helical Pulldown Micropile® is a screw piling system for constructing a grout column around the shaft of a standard AB CHANCE Helical Screw Pile foundation system.
How our foundations are installed
A handheld or machine mounted hydraulic drive head is used to install the screw pile into the ground. Additional displacement plates and extension shafts are bolted onto the shaft and the helical screw piles are pulled downwards. Torque is applied until the necessary load capacity has been achieved. A flowable grout fills the void, surrounding and encapsulating the shaft. The helical screw pile shaft is then cut off and new construction pile plate is attached ready for ring beams to be installed.
Installation of helical screw piles using a mechanical excavator
Will helical foundation piles be suitable for your project?
- Helical screw Piles are suitable for use within a wide range of projects, specifically meeting the needs of projects where:
- There is a need for raked, at angles of up to 45°
- There is any form of soil
- There is a need to support structures through compression and tension
- Where there may be low headroom restricted access
- In demanding projects that are subject to unusual circumstances