Figure 3-16.Column splice with no size change
Figure 3-14.Girder span on a wide flange column.
Figure 3-17.Coped and blocked beam ends.
Figure 3-15.Seated connections.
Beams are generally smaller than girders and are
usually connected to girders as intermediate members
or to columns. Beam connections at a column are
similar to the seated girder-to-column connection.
Beams are used generally to carry floor loads and
transfer those loads to the girders as vertical loads.
Since beams are usually not as deep as girders, there
are several alternative methods of framing one into the
other. The simplest method is to frame the beam
between the top and bottom flanges on the girder, as
shown in figure 3-16. If it is required that the top or
bottom flanges of the girders and beams be flush, it is
necessary to cut away (cope) a portion of the upper or
lower beam flange, as illustrated in figure 3-17.
Bar joists form a lightweight, long-span system
used as floor supports and built-up roofing supports,
as shown in figure 3-18. Bar joists generally run in the
same direction as a beam and may at times eliminate
the need for beams. You will notice in figure 3-19 that
bar joists must have a bearing surface. The span is
from girder to girder. (See fig. 3-20.)
Prefabricated bar joists designed to conform to
specific load requirements are obtainable from
Steel trusses are similar to bar joists in that they
serve the same purpose and look somewhat alike.
They are, however, much heavier and are fabricated
almost entirely from structural shapes, usually angles
and T-shapes. (See fig. 3-21.) Unlike bar joists,
trusses can be fabricated to conform to the shape of
almost any roof system (fig. 3-22) and are therefore
more versatile than bar joists.
The bearing surface of a truss is normally the
column. The truss may span across the entire building
from outside column to outside column. After the
trusses have been erected, they must be secured
between the BAYS with diagonal braces (normally