Sheet piling is an innovative construction material which is most commonly used to create a retaining wall which supports the foundation of a building in the early ages of construction.
Often made from (but not restricted to) steel, these sheets of corrugated metal link together and are partially submerged into the ground.
They create a sustainable barrier between a foundation and any loose ground which might compromise the structure while in its early stages of construction.
This is, of course, the common use for sheet piling. However, it does have a number of lesser known uses which many of us benefit from every day.
With our towns and cities ever expanding, finding somewhere to park is becoming increasingly difficult. In recent years, an effort to counter this has been to build underground car parks. You can read more on this here in this great article from Multi Guide.
Much like in the construction of any building, an underground construction needs a stable foundation. To help create a stable retaining wall, sheet piling is used.
However, there is one big difference. In the construction of structures above ground, once the foundations are put in place and the building begins to take shape, the sheet piling is removed.
In subterranean structures such as a car park, the sheet piling remains throughout the process and becomes part of the structure. It is able to do so because it is both very durable and very strong.
Another use for sheet piling that you might not be aware of is in the construction of railway lines.
Where roads either go over or around hills and valleys, trains tend to go straight through.
If there is a valley, a bridge must be built, if there’s a hill or verge in the way, a trench or tunnel is dug to allow the train to pass.
In order to dig a trench for a railway to run through, there needs to be some form of support at either side to stop landslides covering the tracks.
This is where sheet piling comes in. Often using sheets which are slightly shorter in height in comparison to those used to build buildings or car parks, they create a retaining wall to help create a safe distance from the rail construction line and the potentially loose ground either side.
To get a better understanding of how this works, take a look at this image from Railway Technical. The parts which are annotated “ditch” or “drain” could be places where sheet piling would be present earlier in the construction.
Sea & Flood Defences
Because of the many materials and compositions of sheet piling, it can also be used in structures where it will face serious conditions for many years.
We caught up with contractors Sheet Piling UK who explained how important this fascinating construction material is to the UK’s coastline.
“Because we can design sheet piling in all manner of shapes and sizes, it can be applied to help defend anything near water, be it a town close to a flood-prone river or a seaside town with high tides.”
“Recently we created a number of cofferdams, which are large circular structures which were placed into the sea at the entrance to the Great Yarmouth Harbour”.
“This harbour has struggled with strong tidal breakwaters. These defences helped narrow the entrance and break up the current, allowing for a safer passage for any ships in the future.”
You can see just how this particular job was constructed in a fantastic video on YouTube.