Page 53 - Modern Steel Construction (April 2019)

4. Keep it symmetric. The single-plate shear connection, if symmetrical, can be
installed upside-down or opposite-hand with no effect (see Figures 2 and 3 for examples).
The small increase in material will offset possible fabrication errors, and the symmetrical
pattern helps to avoid base plate-to-column errors and anchor rod placement errors.
Figure 3 shows a base plate with a doubly symmetrical anchor rod pattern.

Fig. 2. Fig. 3.

5. Use single-pass llet welds. If possible, try to use single-pass llet welds. Fig-

3
ure 4 indicates that a 8-in. llet weld requires three passes, which is approximately
three times the cost for a strength increase of 20%. Figure 5 indicates that doubling
the llet weld strength will increase the cost to approximately six times that of a single-

pass weld. The increase in welding cost for multiple-pass welds is generally much
more than the increased material cost required to accommodate single-pass welds.
3 5 3 5
16 – 16 8 8

Fig. 4.

9
Fillet Welds
8
can be more than six times the cost
7
# of Passes
6
Relative Strength
5
twice the
4 strength
at six times
3 the passes
2

1
0
3 5 3 7 9 5 11
16 ¼ 16 8 16 ½ 16 8 16 ¾
Leg Size (in.)
Fig. 5.
Carol Drucker is founding principal of
6. Avoid UDL. UDL (uniform design Drucker Zajdel Structural Engineers; William
load)—which is covered in Table 3-6 of the Thornton is a corporate consultant to Cives
AISC Steel Construction Manual—is not an Corporation; Dominick D’Antonio is vice
economical design choice and can actually be president of W&W Steel Erectors, a division
unsafe. Figure 6 shows two beams framing to a of W&W/AFCO Steel, Patrick Fortney is
column, with one offset from the column line; an associate professor at the University of
each was designed for UDL. This is obviously Cincinnati; and Snehal Supe is a general
not safe in this situation, and a point load near a manager with Pan Gulf Technologies.
Fig. 6. beam end negates the uniform load assumption.
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