Understanding the Different Types of Piling

When it comes to creating solid, stable foundations, piling is a tried-and-tested technique used across the construction industry.

The piling method used for a project can depend on several factors, including:

• ground conditions

• structural loads

• site access

• surrounding buildings

• noise and vibration restrictions

• environmental considerations and

• the installation equipment available

At ABC Anchors, we design and manufacture screw piles, but our in-house team also understands the wider range of piling techniques used throughout construction and foundation engineering.

Our parent company, Autoguide Equipment, also designs and manufactures specialist piling equipment for different installation methods.

Below, we explain some of the main types of piling and where each method may be considered.

1. Screw Piling

Screw piles are steel shafts fitted with one or more helical plates. They are installed by rotating them into the ground using a hydraulic torque head.

Rather than being driven into the soil by impact, the pile advances as the helix cuts into the ground.

One of the important characteristics of screw piling is that installation torque can be monitored as the pile is installed. The resistance encountered by the pile provides information that can be related to its load capacity.

We explain this in more detail in our guide to measuring screw pile torque and calculating load capacity.

Screw piling can be suitable for:

• sites with restricted access

• residential and commercial foundations

• house extensions

• foundation repairs and underpinning

• environmentally sensitive locations

• projects near trees

• temporary structures

• renewable energy installations and

• projects where minimising vibration is important

Advantages of screw piling

Fast installation

Screw piles can be installed efficiently using handheld or excavator-mounted equipment.

mmediate loading

Once correctly installed and connected, screw piles do not require a concrete curing period before they can accept structural loads.

Low noise and vibration

The piles are rotated into the ground rather than installed using repeated impact.

Limited excavation

Installation typically produces considerably less spoil than many excavation-based foundation methods.

Installation can be monitored

Torque readings provide real-time information as the pile advances through the ground.

Can suit restricted access

Different installation equipment can be used depending on the available working space.

If you are considering screw piles for a specific structure, see our screw pile applications and foundation solutions page for further information.

2. CFA Piling – Continuous Flight Auger

CFA piling stands for Continuous Flight Auger piling.

A continuous hollow-stem auger is drilled into the ground to the required depth. Concrete is then pumped through the hollow stem while the auger is gradually withdrawn.

A reinforcement cage can then be inserted into the freshly placed concrete.

Unlike screw piles, CFA piles are constructed in the ground using concrete rather than installing a prefabricated steel pile.

CFA piling can be suitable for:

• urban and built-up locations

• projects requiring relatively low vibration

• medium and large structural loads

• sites where bored pile construction is appropriate and

• ground where maintaining bore stability during installation is important

Advantages of CFA piling

Relatively low vibration

Because the pile is bored rather than impact-driven, CFA piling can reduce vibration compared with some driven piling methods.

Continuous installation process

Drilling and concrete placement form part of a continuous operation.

Useful in certain unstable soils

The continuous auger can help support the bore during the drilling process before concrete is placed.

CFA piling does, however, require specialist rigs, concrete supply and management of excavated material generated during drilling.

3. Augered or Pre-Bored Piling

Augered piling generally involves drilling into the ground before the final pile installation or foundation construction takes place.

Pre-boring can also be used as an enabling technique where ground conditions make direct pile installation difficult.

For example, very dense or obstructed ground may require some form of pre-drilling before another pile type can be installed.

Augered piling can be suitable for:

• dense ground

• mixed ground conditions

• sites containing obstructions

• projects requiring accurate pile positioning and

• situations where reducing resistance during subsequent pile installation is helpful

Advantages of augered piling

Controlled positioning

Drilling equipment can help establish an accurate location and alignment.

Useful in difficult ground

Pre-boring may help overcome dense layers or obstructions that would otherwise prevent the intended pile from progressing.

Can reduce installation resistance

Where appropriate, pre-augering can reduce some of the resistance encountered during later pile installation.

The suitability of pre-boring depends on the pile design and ground conditions. Removing too much soil can affect the way a pile interacts with the surrounding ground, so it should form part of the engineered installation method rather than being treated as a universal solution.

4. Dynamic Piling

Dynamic piling generally involves driving piles into the ground using impact energy.

During dynamic pile testing, measurements taken during hammer impact can also be used to assess pile performance and estimate capacity.

The method differs significantly from screw piling because the pile is driven by impact rather than rotated into the soil.

Dynamic piling can be suitable for:

• certain driven pile systems

• projects requiring dynamic load assessment

• temporary or permanent foundations and

• sites where impact-driven installation is appropriate

Advantages of dynamic piling

Rapid installation in suitable conditions

Driven systems can achieve high installation rates where the ground and site conditions allow.

Performance information

Dynamic testing can provide information about how a pile responds to impact and loading.

Established equipment

Impact-driven pile installation is a long-established construction method.

However, noise and vibration generated during installation may influence whether it is appropriate near neighbouring buildings, sensitive structures or occupied sites.

5. Driven Piling

Driven piles are prefabricated piles installed into the ground using hammering, vibration or other driving techniques.

Pile materials can include:

• steel

• precast concrete and

• timber

The pile is progressively driven until the required installation criteria or bearing stratum are reached.

Driven piling has been used extensively in marine, civil engineering and building projects.

Driven piles can be suitable for:

• marine and coastal projects

• bridges and civil engineering structures

• sites with soft ground above a stronger bearing layer

• high-load applications and

• projects where driven pile installation is suitable for the surrounding environment

Advantages of driven piling

Immediate capacity

Prefabricated piles do not require concrete within the pile itself to cure after installation.

Established technique

Driven piling has a long history within foundation engineering.

Suitable for a range of pile materials

Steel, concrete and timber driven piles are used for different applications.

One consideration is the noise and vibration generated during installation, particularly where piling is taking place near existing buildings or sensitive locations.

What Is the Difference Between Screw Piling and Driven Piling?

The main difference is the installation method.

A screw pile is rotated into the ground using hydraulic torque.

A driven pile is forced into the ground using impact, vibration or another driving action.

This difference affects several practical factors, including:

• installation noise

• vibration

• equipment

• site access

• soil disturbance

• monitoring methods and

• the type of pile that can be used

  
  

Screw piles are particularly useful where low vibration or restricted access is important, although the most appropriate piling solution always depends on the project.

What Is the Difference Between Screw Piles and CFA Piles?

Screw piles are manufactured steel piles that are installed directly into the ground.

CFA piles are formed on site by drilling with a continuous auger and pumping concrete into the bore while the auger is withdrawn.

This means they differ in both construction and installation.

A screw pile can accept structural loading immediately after installation and connection.

A CFA pile requires concrete to be placed and reach the necessary strength before it performs as the completed foundation element.

The appropriate method depends on ground conditions, structural loads, access, site constraints and the foundation design.

Choosing the Right Piling Method

There is no single piling method that is suitable for every project.

The right approach depends on factors including:

• soil conditions

• foundation loads

• pile depth

• available working space

• access for machinery

• nearby structures

• acceptable noise and vibration levels

• groundwater

• environmental constraints and

• project programme

Ground investigation and structural engineering are therefore important parts of selecting a foundation system.

At ABC Anchors, we specialise in screw piling. However, we also recognise the importance of understanding other piling methods so that screw piles are specified where they are appropriate for the site and structural requirements, rather than used as a default solution.

Considering Screw Piles for Your Project?

If screw piling appears suitable for your project, the next step is to move from understanding the piling method to establishing the actual foundation requirements.

At ABC Anchors, we design and manufacture screw piles for foundation projects, with standard pile diameters ranging from 60 mm to 89 mm and torque limits across the range from 4 kNm to 22.5 kNm.

From there, you can explore our screw pile applications and foundation solutions available for different structures, including:

• underpinning and foundation repairs

• new-build foundations

• bridge foundations

• house extensions

• temporary structures

• foundations near tree roots and

• solar panels and wind turbines

Understanding Screw Pile Torque and Load

If you have moved beyond comparing piling methods and are considering screw piles from an engineering perspective, installation torque is an important part of the process.

As a screw pile is rotated into the soil, the torque required to continue installation can be monitored.

This provides information about the resistance being encountered by the pile.

ABC Anchors uses the recognised relationship:

Qu = Kt × T

where:

• Qu is the ultimate pile capacity

• Kt is the empirical torque factor and

• T is the average installation torque

The appropriate safe working load is then determined using the relevant design and safety factors.

Read the full explanation in our guide to screw pile torque and load calculations.

See How Screw Piles Are Used on Real Projects

Understanding different piling methods in theory is useful, but real installations show how foundation choices work in practice.

ABC Anchors' screw pile case studies cover completed foundation projects and demonstrate how screw piles can be adapted to different structures, loads, access restrictions and ground conditions.

These examples can be particularly useful if you are comparing screw piling with another foundation method and want to understand how the system performs on actual sites.

Talk to ABC Anchors About Screw Piling

If you already have information about your ground conditions, loads or proposed structure, ABC Anchors can help you identify the appropriate next steps for a screw pile project.

You can start with the screw pile range, explore the applications and solutions, or review the technical information on torque and load calculations.

For project-specific requirements, contact us today on +44 (0)1380 850885.

Frequently Asked Questions About the Different Types of Piling

1. What are the main types of piling?

Common piling methods include screw piling, CFA piling, augered or bored piling, driven piling and other specialist pile installation methods. Each uses a different technique to transfer structural loads into suitable ground.

2. What is screw piling?

Screw piling uses steel piles fitted with helical plates that are rotated into the ground using hydraulic installation equipment. Installation torque can be monitored as the pile advances, helping establish whether the required ground resistance is being achieved.

You can see our screw pile range here.

3. What is CFA piling?

CFA stands for Continuous Flight Auger. A hollow-stem auger is drilled into the ground before concrete is pumped through the auger as it is withdrawn. Reinforcement can then be inserted into the wet concrete.

4. What is driven piling?

Driven piling involves installing a prefabricated pile by forcing it into the ground using impact, vibration or another driving method. Driven piles may be manufactured from steel, concrete or timber.

5. What is augered piling?

Augered piling involves drilling into the ground using an auger. Depending on the foundation system, the drilled hole may form part of the finished pile or may be used as a pre-bore before another pile is installed.

6. Which type of piling is best?

There is no single piling method that is best for every project. The appropriate solution depends on factors such as ground conditions, structural loads, access, nearby structures, environmental restrictions and the required installation depth.

7. What type of piling is suitable for restricted access?

Screw piling can be particularly useful on restricted-access sites because smaller installation equipment, including handheld torque heads, can be used in some circumstances. The correct solution still depends on the pile specification and structural requirements.

8. Which piling method creates the least vibration?

Screw piling generally produces low levels of vibration because the pile is rotated into the ground rather than installed by repeated impact. CFA and other bored piling methods can also be selected where controlling vibration is important.

9. Do screw piles need time to cure?

No. Screw piles are manufactured steel foundation elements and do not rely on freshly poured concrete within the pile to cure after installation. Once correctly installed and connected, they can accept structural loads immediately.

10. How is screw pile capacity checked during installation?

Installation torque is monitored as the screw pile advances through the ground. Torque can be related to ultimate pile capacity using an empirical torque factor. At ABC Anchors, we explain the process in our dedicated guide to screw pile torque and load calculations.

11. Where can screw piles be used?

Screw piles can be used for many foundation applications, including residential and commercial buildings, extensions, underpinning, temporary structures, bridge works, foundations near trees and renewable energy installations.

See our full range of screw pile applications and solutions.

12. Are screw piles suitable for underpinning?

Yes, screw piles can be used as part of an engineered underpinning system where existing foundations require additional support. The piles transfer structural loads through unsuitable ground to more competent material below.

Read more about screw pile underpinning and foundation repairs.

13. How do I know whether screw piles are suitable for my project?

The decision should be based on the proposed structure, ground conditions, loads, access and foundation design. Ground investigation and engineering information may be required before the appropriate pile system can be confirmed.

You can contact us today on +44 (0)1380 850885 discuss the requirements of your project.

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