composing the area that is exposed to wave action. In
repair of the damage, consideration must be given to
the cause of damage, such as an unusually severe
storm, need for strengthening of structure, and too
steep side slopes. Unless it is evident after study by
design engineers that changes in design are required,
the structural damage should be repaired with the same
materials used in the original to restore the structure
to its original strength, elevation, and cross section.
Depressions washed out of the bottom in the vicinity
of structures should be replaced with sand or
GRANULAR materials up to the original level before
replacing stone. You can do this either by dumping
from the undamaged part of the structure or by placing
the materials from a barge from a floating derrick.
Structures, made of cut stone and cast concrete,
made into shapes and fitted up tightly together, or laid
up with mortar or similar material, are considered
masonry structures. Units may be bonded together by
overlapping, by metal clamps, dowels, or bed plugs,
or by shapes of the blocks (fig. 7-29). All metal
fastenings should be zinc-coated and well bedded in
mortar. Sections of masonry that have washed out or
have been damaged should be completely rebuilt,
bonding the units to each other or using metal
fastenings as necessary. Masonry walls that have
cracked because of unequal settlement can be rebuilt,
adding reinforcing bars, as shown in figure 7-30.
Repair of cracked walls should be delayed until
settlement is complete if possible. Where sections of
walls have been displaced by sliding, an investigation
should be made to determine the cause before it is
rebuilt. If water builds up back of the walls, the weep
holes should be cleaned and new ones installed to
relieve the pressure. Walls that fail because they are
inadequate should be redesigned before they are
rebuilt. It is advisable to provide clamps for
reinforcement where the displacement of a wall is
minor. If it is not necessary to rebuild the wall, it can
be reinforced by drilling holes down through the wall
at the rear of displacement and a short distance beyond,
inserting steel rods in the holes and filling the holes
with cement mortar (fig. 7-31).
The use of earth for waterfront structures is
confined largely to dikes and levees. It is also used for
the interior of such structures as causeways, moles,
and breakwaters; as backfill for quay walls and similar
Figure 7-29.Anchoring masonry blocks.
Figure 7-30.Repair to cracked masonry walls.