As combined Sheet pile walls often have the most efficient weight per square foot of wall for load-bearing requirements of over 70 in3/ft (~3,800 cm3/m) the bidder will likely need to purchase, transport and install less steel than with other sheet piling systems. As steel is often priced by weight, a lighter option may often be less expensive in material costs. However, as steel producers know, those who have less efficient options may compensate the tonnage pricing to equalize the square foot / meter of wall costs.
Combined steel sheet piling walls are often quicker and easier to install than heavier z-sheet piles when the sheet piles are over 50 feet (~15 m) in length, due to the fact that only a fraction of the system needs to be driven to full depth under normal project conditions.
There are various types of combined steel walls used by the U.S. Army Corps of Engineers on projects all over the world. The following is a description of the most popular combined sheet piling walls:
Steel walls with u-shaped sheet piles incorporate steel sheets comprised of a web with two flanges which form a shape similar to the letter U. The interlocks of a single U sheet pile are positioned at both flange ends and are located on the wall axis.
Like Z sheet piles, U sheet piles are best in lighter load or temporary applications.