These are historically one of the most efficient geotechnical structures that are used for soil retention, water cut-off, or trench supporting systems. Sheet piles are steel prefabricated sections in U shapes or Z shapes with specific dimensions that are driven into the soil in rows of interlocking pieces to form a continuous wall. They are also used for construction of cofferdams. Sheet piles just like other embedded retaining walls may be cantilever or tied back or internally supported walls. They are driven to the soil using vibrators or hammers. Due to their simplicity of execution they are in high demand in marine or river banks protection, bridge construction and other structures which needs retaining structures. They may be temporary or permanent. Depending on their design life their durability is investigated by corrosion effects as the sheet piles decrease in thickness with time. Corrosion protection may be by coating or electrical cathodic protection.
In worst sea splashing zones the rate of corrosion may be calculated and the thickness of the sheet piles may be determined based on design life and the structural requirements.
Although they are not 100% water tight but they efficiently delay the water flow and their water tightness may be increased by adding rubber to the interlocking keys.
If used in double wall cofferdams the soil filling the distance between the two leave of the cofferdam is the major contributor to the stability of the wall and hinders the water flow from flooding the protected site. In cellular cofferdams sheet piles are used in circular patterns forming great walls to prevent water flow from one side to another.
Sheet piles are manufactured in certain lengths. Most common are the 12m and 18m lengths. Depending on the excavation or retention depth sheet pile maybe cut or extended by welding to different lengths. Anchored sheet piles are used but the most common tie backs are rod connected to concrete blocks or smaller row of sheet piles in the passive zone out of the expected failure wedge to provide the required resistance.
Recently, sheet piles manufacturing improved to use cold formed sections and synthetic or vinyl products which have higher resistance to corrosion and more durability.
APCC’s double wall cofferdam of The Jewel of the Creek site is very famous in Dubai and managed to keep the site dry from water flow from Dubai Creek for many years successfully.
The company installed sheet piles for many projects of marine works, earth retaining works and water cut-off works. APCC is always invited to any mega-sheet piling works in the regions of activity.