Piling foundations are a key component in many different structures such as houses, bridges, viaducts and roads providing them with the stability they need. But what are piling foundations and more importantly how do they work?
Within this blog post we are going to take a closer look at piling foundations by examining what they are, where and when they are needed and the different types. By doing this hopefully you will get a clearer understanding of the piling process and the reason why it has become a mainstay of the construction industry.
What Is Piling?
Piling involves the insertion of cylindrical columns usually manufactured from steel or concrete into the ground to provide a base for a building. Piles are usually required in areas that have poorly performing soil or earth to spread the building’s load and provide it with a firmer base.
Piling foundations are considered to be a cost effective solution when it comes to dealing with corrosion and have proved to significantly increase the life expectancy of all manner of different structures.
When Do you Need Piling Foundations?
Piling is usually required when a standard shallow foundation would not be enough to support the weight of a structure. Piling foundations are routinely used if the soil or earth surrounding a structure is not considered suitable or if you are working on a large project that will need additional support.
Using piling foundations is also recommended if:
- There is a high water table
- Weak soil: When the top layer of soil is weak or unable to support the building’s weight
- The area around a building has a low load bearing capacity like clay or peat
- Existing trench foundations are unstable or it would be much more expensive to remove them
- Other methods are prohibitively expensive
What are Piling Foundations Made Of ?
Foundation Piles can be manufactured from metal, concrete, wood or steel. Designed to provide support buildings surrounded by weak soil foundation piles are hammered into the ground. Piled foundations are required to carry heavy loads so it is imperative that care is taken during the design process. Piles need to be placed so the load is spread evenly across the site to ensure maximum support for the structure.
What are the Different Kinds of Piling Foundations
Piling foundations are usually divided into categories based on their design and the way they are supplied, and installation process. When considering which type of piling is best suited for their specific project construction companies will generally tackle the following factors into account:
- The Depth of the Excavation
- The angle at which the pile will be installed
- Any environmental issues that may impact on local residents
The different kinds of Piling Foundations Include:
Driven piles (displacement piles)
When driven piles are hammered into the ground using extreme force the soil is compacted meaning it comes denser which increases its load bearing capacity. Driven piles are cast off site prior to use which means they can be manufactured in line with the needs of the particular project.
Bored piles (replacement piles)
When creating a bored pile a hole is first drilled in the earth which is then filled with concrete. Created in situ by casting the pile directly into place, a bored pile provides you with excellent stability. It is often the preferred choice for residential developments because less vibration is generated during the installation process.
End-bearing piles
End bearing piles function by transferring most of the load directly to the base of the pile after it reaches a solid layer of earth. This process creates a column that penetrates weaker ground and anchors into the more stable layer beneath, providing a strong foundation for the structure.
Friction piles
A friction pile uses its height to transfer the force a building generates into the soil around it. If you use this method of piling the size of the load you can support is dictated by the length of the pile. This means that deeper piles are able to support heavier weights. Friction piles may also be referred to as floating piles.
Screwed Piles
If you use the helix end you can insert screw piles into earth the same way that you would fix a screw into wood. This is why this type of pile is considered a good solution when you are trying to minimise damage during the installation process. This method of piling can often be a more cost effective solution.
What is the Difference between Piling and Mini Piling?
The main difference between piling and mini piling is the size of the piles used and the equipment used to install them:
In traditional piling a pile driver is used to hammer piles into the ground. Whereas with mini piling smaller narrower piles are used which can be installed using lighter and more manoeuvrable equipment. Mini or micro piling is ideal where access is restricted or in existing structures that have limited headroom where the use of traditional piling methods would be difficult or impossible.
Hopefully the information provided in this article will have given you a better understanding of piling and why it is widely used in all areas of construction. If you would like to discuss a specific project get in touch with the team here at WL Piling who will be only too happy to help.