A cantilever bulkhead derives its support solely from ground penetration; therefore, the sheet
piles must be driven deep enough to resist overturning. Cantilever bulkheads are susceptible failure due
to toe scour because this reduces the effective embedment of the piling.
An anchored or braced bulkhead gains additional support against seaward def lection from
embedded anchors or from batter structural piles on the seaward side. Anchors are commonly a r of piles
or deadmen driven or buried a distance behind the bulkhead. Connections between the anchors and wall
should be wrought iron, galvanized or other suitably corrosion-protected steel. Plain carbon steel should
not be used for long-term protection. Horizontal wales are generally located in the upper one-third the
wall height above the dredge line. For low bulkheads, they m be at or near the top of the structure. The
wales distribute the anchors, the lateral loads on the structure. An anchor system is not well suited to
sites with buildings close to the shoreline because of the distance needed between the bulkhead and
anchor In that case, brace piles ma be used in lace of anchoring.
Subsurface conditions determine the type of sheet piling that can be used. Steel sheet piling can
be driven into hard soil and some soft rock. Aluminum and timber sheet piling can only by driven or
jetted into softer soil.
The advantages of sheet pile bulkheads are their relatively long and maintenance-free lives, and
their uniform appearance. Their disadvantages include the special pile-driving equipment required to
Treated Timber. Well-designed and built timber structures have long been recognized as viable
and economical materials for bulkhead construction (Figure 29). Figure 30 illustrates the common types