What are Screw Piles?
Screw Piles are long, usually steel anchors that drill deep into foundations, acting similarly to a screw into wood, making the foundations more secure. Screw Piling is usually the most desirable piling choice when a higher load is required, if the ground is much softer, and in some instances of residential projects if there is lower noise pollution needed.
Interesting fact – Screw Piles were invented in 1838 by a Blind Civil Engineer from Ireland called Alexander Mitchell. He found that by screwing in the foundations, lighthouses that were based offshore in shallow water environments became more secure as they became anchored into the ground.
What are the benefits of using Screw Piles over Driven Piling?
Screw Piles tend to have a much lower environmental impact – this is because screwing into the ground reduces the displacement of soil. This means less time and effort needs to be concentrated on the removal of soil from the site.
Furthermore, less vibration occurs through screw piles than through driven piles, meaning there is much lower sound pollution as well as a lesser impact on the soils in the surrounding environment caused by the hammering of a driven pile. This is vital for projects being done on difficult and loose terrain.
Additionally, in most instances, Screw Piling is an easier way to install the foundations, as they only require one machine for installation, meaning it costs less too.
Typical installation times tend to be much quicker for Screw Piling since there is no need to dig or allow time for setting. This means that the Piles can instantly bear weight, which is crucial for urgent projects.
Projects that have low headroom space or limited access are perfect for Screw Piles as the design of the equipment means that their modular design allows for their extension sections to be made in a variety of sizes.
In what projects are Screw Piles best for?
Initially, Screw Piles were created and concentrated in the nautical industry, for use on Lighthouses. However, they’re now used in many industries, such as rail, telecommunications, roads and housing – essentially any work that needs foundations quickly.
Fortis Foundations most recently had to utilise Screw Piling in a project for a railway client. They urgently required a new platform canopy, so our team got to work by understanding the scope and location of the proposed build. It required 244.5mm diameter screw piles to support the canopy which was installed quickly and professionally. Screw Piling in this situation was key because any sort of excessive vibration could have a huge impact on the groundwork in and around the train station.
Are there any disadvantages of using Screw Piles?
Disadvantages for any type of Piling just mean that another form is more useful, as Screw Piling is better adjusted to deal with soft ground soils in compact areas.
The biggest issue with Screw Piling is that it can be difficult to penetrate hard ground layers such as rock. In this instance, a Driven Pile would be more appropriate as it is hammered into and through the tough rock.
Whilst soils which have large grain sizes, such as gravel and cobble deposits, are difficult for Screw Piles to correctly advance.
There are also structural limitations to the effectiveness of Screw Piles. Manufacturers tend to give Screw Piles a ‘torque rating’ which defines the limit to the amount of torque (force) that can be applied to the Screw Pile before the integrity of the structure becomes compromised.
If you have a project that requires strong foundations, don’t hesitate to get in touch with us today:
Telephone: 01442 731 321