| FOUNDATIONS
Foundations vary according to their use, the soil-bearing capacity,
and the type of material available. The
material may be cut stone, rock, brick, concrete, tile, or wood, depending
on the weight the foundation is to
support. Foundations may be classified as wall or column (pier) foundations.
WALL FOUNDATIONS
Wall foundations (Figure 4-5) are solid their total length and are usually
used when heavy loads are to be
carried or where the earth has low supporting strength. These walls may
be made of concrete, rock, brick, or
cut stone, with a footing at the bottom. Because of the time, labor, and
material required to build it, this type o
wall will be used in the TO only when other types cannot be used. Steel-rod
reinforcements should be used in
all concrete walls.
Rubble stone masonry is used for walls both above and below
ground and for bridge abutments. In military
construction, it is used when form lumber for masonry units is not available.
Rubble masonry may be laid up
with or without mortar; if strength and stability are desired, mortar
must be used.
Coursed rubble is assembled of roughly squared stones in such
a manner as to produce approximately
continuous horizontal bed joints.
Random rubble is the crudest of all types of stonework. Little
attention is paid to laying the stone in courses.
Each layer must contain bonding stones that extend through the wall. This
produces a wall that is well tied
together.
COLUMN OR POST FOUNDATIONS
The use of column or post foundations constructed from masonry or wood
saves time and labor. The posts or
columns are spaced according to the weight to be carried. In most cases,
the spacing is 6 to 10 feet apart. The
sketches in Figure 4-6 show the different types of posts with appropriate
types of footing. Wood posts are
generally used, since they are installed with the least time and labor.
When wood posts extend 3 feet or more
above the ground, braces are necessary (Figure 4-7).
 
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