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Steel Designers' Manual - 6th Edition (2003)
946 Tolerances
Table 31.5 (contd )
9.6.15 Profile Steel Floor Decking
Deviation of dimension between
deck edge trim and peñmeter beam
Actual
beam
Note: Deviation (as shown) beveen actual
beam centre line and intended beam _______________
centre line arises from other
permitted tolerances (e.g. 9.6.4)
Generic profile deck may
span either direction
L±1Omm
in steps not exceeding the permitted deviation. No more than three layers of shims
should be used at any point, and preferably only one or two. The shims (and the
lengths of columns) may be held in place by means of a partial penetration butt
weld extending over the shims (see Fig. 31.5(a)).
In bolted compression splices, bolted ‘finger’ shims (shaped as indicated in
Fig. 31.5(b)) can be used.
In some cases shims can be driven in, but if so they need to be fairly robust
(usually over 2 mm thick), so shims of various thicknesses are needed throughout
the joint. Driven shims are best limited to vertical joints e.g. between a beam end
plate and a column. More commonly the joint must be jacked or wedged open (or
else the upper portion lifted by a crane) so that the shims can be inserted. Tapered
shims are particularly difficult to insert; as they are not necessary they are best
avoided.
31.5.7 Values for erection tolerances
The values for erection tolerances are given in Table 31.5. Each of the specified criteria
should be considered and satisfied separately. The permitted deviations should
not be considered as cumulative, except to the extent that they are specified relative
to points or lines that also have permitted deviation. These values represent
current practice and are taken from the fourth edition of the NSSS.
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