What should you know about sheet piles?
- Basics of sheet piling
- Types of sheet piles
- Uses of sheet piles
When it comes to construction materials, you’ve heard about the typical steel pipes, frames, roofing, corrugated sheets, rebar, and the like. But sheet piling is a term that’s probably unfamiliar to you. Unlike the materials mentioned above, sheet piles sport a specialized design that allows them to be seamlessly attached to one another. When interconnected in a single formation, sheet piling creates a sturdy structure that’s used for wall retention purposes. In this guide, you’ll discover everything you need to know about sheet piles and more — from its basics, the types, and the uses. Read on to learn more.
Basics of Sheet Piling
Sheet piles are sectional construction materials that consist of a steel plate that has interlocking edges on both sides. At the end of these webs, you’ll find grooves and a tongue-shaped portion where other sheet piles can be locked together. Although this is the most common design for steel sheet piles — known as the Larssen shape — sheet piles may also come in a variety of designs.
Some sheet piles, for example, have a Z-shaped body, while some feature a straight webbing that’s lacking the contours of both the Larssen and Z-shapes. Meanwhile, pan-type sheet piles are designed only for light loads. They’re not intended for high-pressure situations such as harbor docking or excavating.
Sheet piling can be done for both temporary and permanent structures. You’ll oftentimes find sheet piling works in excavation zones, wherein it acts as a wall-retaining implement. This is done to prevent soil erosion. It also serves as a border by which the soil is prevented from spilling over to the main excavating site.
Types of Sheet Piles
Classifying sheet piles may depend on the installation pattern and the kind of material used. For the first category, there are three types of piling methods, namely anchored sheet piling, cofferdams, and cantilever. In each of these methods, any type of sheet piling material can be used, from steel sheets, pre-stressed concrete, aluminum, or even fiberglass.
Anchored Sheet Piling
Anchored sheet piling is done for wall structures that don’t exceed heights of 5 meters. In this type of sheet piling, soil penetration is minimized due to the anchors that offer enhanced stability for the sheet piles, in addition to the passive resistance already provided by the soil.
This type of sheet pile has also been pre-stressed during manufacturing. This is to ensure that the sheet piling work is capable of withstanding the compressive forces that will occur once in use.
Cofferdams are enclosures that are built well below the surface in order to prevent water or soil from getting to the main work site. While their primary use is for temporary support, they can be part of a permanent fixture by adding waterproofing parts and other sealants to create a watertight enclosure.
Like many sheet pile structures, cofferdams are cost-effective and don’t take time to set up. They are also designed to support both vertical and horizontal loads, especially when steel sheet piles are used.
Similar to anchored sheet piling, the cantilever formation is done when the height of the wall needs to be less than 4.5 meters. This sheet piling is only supported at one end, which allows for flexibility. However, it may not be ideal for wall support that exceeds the range mentioned above.
Uses of Sheet Piles
As mentioned before, sheet piles are used for providing support for below-level or underground wall enclosures. With this in mind, the uses of sheet piling can vary — from excavation zones, basements, underground structures, cofferdams, ship harbors, marine sites, and the like. In order to retain the structural integrity of the sheet piling, the work should be configured according to the compressive forces and loads on the sheet piles once the structure is already in use.
For example, when sheet piles have been installed in sites where the subsoil contains compacted areas and hard rocks, the sheet piles might not easily penetrate into the ground. To fix this, vibration forces are applied in order to break up the dense components and allow the sheet piles to be easily driven into the soil layer.
Another example is with sheet piling cofferdams — since sheet piles are mainly interlocked without the use of welding or adhesives, they won’t be suitable to prevent water from seeping. This problem can be mitigated by adding sealants to the interlocks. To prevent damage to the structure itself, the sheet piles are also supported by braces or wales which are installed parallel along the excavated area.
In this guide, you were provided with an overview of everything you need to know about sheet piles. While these structures may appear similar to walls, they are able to withstand far greater pressure forces exerted by their surroundings. This is why you’ll oftentimes find sheet piles installed in a series of excavation sites, wall enclosures, and underwater systems. The unique interlocking mechanism of sheet piles — particularly steel sheet piles — makes them a durable and practical construction fixture without the downsides.