There are several types of sheet pile. They can be categorized in many ways, one of these is through their material composition. The common types of sheet piles based on the material are wood, steel, concrete, light-weight aluminum, and polyvinyl chloride (PVC).
The earliest type of sheet pile is the wooden sheet pile. Wooden sheet pile can be classified as ordinary plank or tongue and groove.
The types of wooden sheet pile commonly use for shallow soil retention and the low budget project is planking. If the wall needs to be water-tight, the sheet pile are to be inter-lapped with each other. Each pile is made up of two or rows of planks, either spiked or bolted to one another depending on how water-tight the retention must be.
Wakefield or tongue and grooved sheeting are generally used if complete water tightness or pressure is desired for the retention wall. To facilitate the driving of the piles, they are usually beveled at the bottom. The beveled end helps in driving the sheet pile and also prevents bruising if the piles encounter a hard stratum.
Interlock of a groove and tongue wooden sheet pile
Series of steel sheet pile for wall retention.
Stock pile of cold-rolled sheet pile.
No one can argue that the most in-demand sheet pile in the industry right now is the steel sheet pile.
A long steel sheet is rolled in the desired profile section such as U and Z with interlocking edges. Among these steel sheet piles, we can say that the most famous profile is the Larssen Steel Sheet Pile. It was designed by Tryggve Larssen in 1906. Larssen sheet pile is a long sheet with alternating indents and outdents along its profile to increase bending capacity.
Among these, the most common is the U-type. It is the newer version of steel flat pile, bent and rolled to create a U-shape profile. It is also the most common sheet pile we use in the Philippines.
The most cost-effective type of sheet pile today is the Z-type. It has the largest strength to weight ratio because of its large width and also the location of its interlock adds to its bending capacity.
Profile of Z-type sheet pile with Larssen interlock
Profile of a U-type sheet pile.
However on very specific instances, Omega type sheet pile might be the best to use.
Interlocking Omega steel sheet piles.
Another type of sheet pile based on material composition is the concrete sheet pile. It can be classified as pre-cast or pre-stressed.
Precast concrete piles are made in square or rectangular cross-section and are driven similar to wooden piles to form a wall. The interlock between two piles is normally provided with the help of the tongue and groove joint.
The piles are reinforced to avoid the formation of cracks due to rough handling or shrinkage stresses. The piles are normally beveled at their toe to facilitate smooth driving of a pile against the already driven one.
Reinforced concrete sheet piles are similar to pre-stressed concrete but are bulky, heavy, and brittle so their popularity is superseded by steel sheet piles.
(a) Rectangular reinforcement, (b) Trapezoidal reinforcement on pre-cast concrete
On the other hand, prestressed concrete sheet piles are reinforced on both faces so that they could be handle from either side. They are comparatively lighter in weight, more durable, and economical in the long run than pre-cast concrete sheet piles. They are advantageous on seawater since the danger of cracking of concrete is negligible and also the corresponding danger of corrosion of pile reinforcement is reduced.
Aluminum sheet piles are used if the bending stress is small and corrosion is the main factor to consider. Aluminum sheet pile is now being used for over 40 years due to its stiffness and corrosion-resistant property. However, in the Philippines, the aluminum sheet pile is not popular because of its scarce supply and expensive cost. The alternative we used locally is corrosion coated steel sheet pile.
River side which uses PVC sheet pile as protection.
In areas where corrosion protection is the main factor considered, we can use PVC sheet piles. PVC or poly-vinyl chloride sheet pile has gained popularity because of its aesthetic and weight. PVC is easy to transport and are corrosion resistant that’s why they are more commonly used in water retention area. They are also popular on parks, malls, and other establishments that require more sophisticated looking sheet pile since PVC has a smooth texture and are easy to paint. PVC sheet piles are also cheaper than steel but they are only suitable for small stress loading walls.