Figure 8-33.Steel sheet-pile bulkhead.
A BULKHEAD serves the same general purpose as
a seawall, namely, to establish and maintain a stable
shoreline. However, while a seawall is self-contained,
relatively thick, and is supported by its own weight, the
bulkhead is a relatively thin wall. Bulkheads are
classified according to types of construction, such as the
Wood sheet-pile bulkhead
Steel sheet-pile bulkhead
Concrete sheet-pile bulkhead
Most bulkheads are made of steel sheet piles, as
shown in figure 8-33, and are supported by a series of
tie wires or tie rods that are run back to a buried
anchorage (or deadman). The outer ends of the tie rods
are anchored to a steel wale that runs horizontally along
the outer or inner face of the bulkhead. The wale is
usually made up of pairs of structural steel channels that
are bolted together back to back.
In stable soil above the groundwater level, the
anchorage for a bulkhead may consist simply of a buried
timber, a concrete deadman, or a row of driven and
buried sheet piles. A more substantial anchorage for
each tie rod is used below the groundwater level. Two
common types of anchorages are shown in figure 8-34.
In view A, the anchorage for each tie rod consists of a
timber cap, supported by a batter pile, which is bolted
to a bearing pile. In view B, the anchorage consists of
a reinforced concrete cap, supported by a pair of batter
piles. As shown in the figure, tie rods are supported by
piles located midway between the anchorage and the
Bulkheads are constructed from working drawings
like those shown in figure 8-35. The detail plan for the
bulkhead shows that the anchorage consists of a row of
sheet piles to which the inner ends of the tie rods are
anchored by means of a channel wale.
The section view shows that the anchorage will lie
58 feet behind the bulkhead. This view also suggests
the order of construction sequence. First, the shore and
bottom will be excavated to the level of the long, sloping
dotted line. The sheet piles for the bulkhead and
anchorage will then be driven. The intervening dotted
lines, at intervals of 19 feet 4 inches, represent
supporting piles, which will be driven to hold up the tie
rods. The piles will be driven next, and the tie rods then
set in place. The wales will be bolted on, and the tie
rods will be tightened moderately (they are equipped
with turnbuckles for this purpose).
Figure 8-34.Two types of tie-rod anchorages for bulkheads.