Pile foundations are a key component of modern day construction providing improved stability and load bearing support for any type of structure that is built on poor quality soil. Pile foundations are routinely used in the construction of all different types of structure such as bridges and multi storey buildings.
The aim of a pile foundation is to help distribute the weight of the structure to stronger layers of soil located well below the surface. However, not all pile foundations are the same, so within this blog post we are going to examine the different types and when they should be used. We’ll also take a closer look at the two main categories which are end bearing and friction piles and the part they play in the construction industry.
What Are Pile Foundations?
Pile foundations are made up of long slim columns that are driven into the ground to provide support to heavy loads. Pile foundations are typically made out of steel, reinforced concrete or occasionally timber. Pile foundations are generally used when a structure is being built on soil that may be soft or waterlogged and as such cannot provide sufficient load bearing capacity.
Pile foundations are classified by their function, make up and how they are installed. The one that is best for your particular project will depend on a number of different factors such as soil conditions, load, the type of structure, environmental considerations and the depth of the excavation.
End-Bearing vs. Friction Piles
End-Bearing Piles
An end bearing pile will distribute the load from the topsoil to a stronger layer of soil or rock below. This gives structures the ability to withstand heavy loads. Made from concrete, steel or timber end bearing piles are driven or bored into the ground until they come to a hard layer. The size of the pile you need is dependent on soil conditions around the structure and the load you need to support.
Friction Piles
Friction piles are reliant on surface friction between the pile and surrounding soil to spread out the load. As opposed to boring down to reach hard layers of rock or stronger soil these piles get their support from the resistance of the surrounding soil along their length. This means that friction piles are the perfect choice when building in areas where the cost of reaching bedrock is not financially viable.
Types Of Pile Foundations
Driven Piles
Driven piles are prefabricated piles made of materials like concrete, steel, or wood. As the name suggests this type of pile is driven into the ground using pile-driving machinery. Highly durable with the capability to support extremely heavy loads, driven piles are a popular choice for projects where environmental concerns such noise and vibrations during installation are not an issue.
Are Driven Piles Environmentally Friendly?
If you use sustainable materials, Driven piles can be eco-friendly However, the noise and vibrations associated with pile driving can have a negative impact on the environment so measures to mitigate this problem will be needed.
Bored Piles
Bored piles are constructed by drilling a hole into the ground, which is then filled with concrete. Because it helps keep vibrations to a minimum, bored piling is often the chosen method for projects located near other buildings or in urban areas. If you want to enhance the load bearing capacity of bored piles they can be reinforced with steel.
How Are Bored Piles Different From Driven Piles?
While you install driven piles by forcing them into the soil, you put bored piles in place by drilling a hole in the ground and filling it with concrete. For this reason bored piles are much quieter causing less disruption to the surrounding area which makes them the ideal solution for sensitive sites.
Driven and Cast-In-Situ Piles
This is a combination of both driven and bored piles. To start with, a hollow steel casing is driven into the ground, and then filled with concrete which forms a pile. You can either leave the casing in situ to provide reinforcement or remove it if you are happy the concrete alone will suffice. This method gives you the benefits of both driven and bored piles, as it balances both cost and performance.
Aggregate Piles
Aggregate piles are where compounded aggregate such as stone and gravel is used instead of concrete. These piles increase the load-bearing capacity of weak soils by compacting and reinforcing them. Regarded as a cost effective and environmentally friendly solution aggregate piles are routinely used on lighter structures or where you need to improve the quality of soil as opposed to using a deep piling method.
Are Aggregate Piles Suitable For Heavy Structures?
Aggregate piles are usually better suited for lighter structures or as soil stabilisers. In the case of heavier loads it is advisable to use one of the other methods such as bored or driven piling.
Benefits Of Using Foundation Piling In Construction
The advantages offered by Pile foundations have made them an indispensable part of modern construction:
Versatility: Because they are suitable for use in various soil conditions including weak or waterlogged soils, foundation piles can be used in all different types of construction projects.
Load Capacity: They provide exceptional support for heavy structures by transferring loads to deeper, more stable layers.
Durability: Constructed from materials such as steel or reinforced concrete Piles can last for decades, even in toughest environments.
Improved Soil Stability: Certain types, like aggregate piles, enhance the strength and stability of the surrounding soil.
Adaptability: The range of options available to you such as drive or bored piles, piling can be adapted for use on a wide range of projects in line with their specific needs and the conditions on site.
Pile foundations play a critical role in ensuring the safety and longevity of structures built on weak or unstable soils. Hopefully the information in this blog post will leave you better informed about the different types of piling and ensure that you make the correct choice for your specific project.
If you would like any more information contact the team here at WL Piling who will be able to provide you with all the details of our range of high quality competitively priced Piling solutions.
