283757893275

300 Barry’s Advanced Construction of Buildings
Universal
column
Angle
cleat
Main
beam
Beam
Plate welded
to beam
cutting bolted
to column
Figure 5.22 External beam to column connection.
Cleat connections of beam to column (Figure 5.20) are generally assumed to provide a
simple connection in structural analysis and calculation, as there is little restraint to simple
bending by this type of end connection of beams. This simply supported (unrestrained)
connection is the usual basis of design calculations for structural steel frames as the simple
connection provides little restraint to bending, whereas a welded end connection is rigid
and affects beam bending.
Figure 5.22 is an illustration of the connection of a main beam to a column on the
external face of a building with the external face beam connected across the outside flanges
of external columns. The internal beam is supported by a bottom seating angle cleat and
top angle cleat. The external beam is fixed continuously across the outer face of columns
to provide support for external walling or cladding that is built across the face of the frame.
This beam is supported on a beam cutting to which a plate has been welded to provide a
level seating for the beam and for bolt fixing to the beam. The beam cutting is bolted to
the flange of columns. A top angle cleat is bolted to the beam and column to maintain the
beam in its correct upright position.
The connection of long column lengths up the height of a structural steel frame is usually
made some little distance above floor beam connections, as illustrated in Figure 5.23. The
ends of columns are accurately machined flat and level. Cap plates are welded to the ends
of columns in the fabricator’s shop and drilled ready for site bolted connections. Columns for
the top floors of multi-storey buildings will be less heavily loaded than those to the floors
below and it may be possible to use a smaller section of column. The connection of these
dissimilar section columns is effected through a thick bearing plate welded to the machined
end of the lower column and splice plates welded to the outer flange faces. The thick bearing
plate will transfer the load from the smaller section column to that of the larger column.
The splice plates provide a means of joining the columns. The upper column is hoisted into
position on the bearing plate, and packing plates are fitted into place to make up the difference
between the column sections. The connection is then made by bolts through the