Shearson Lehman/American Express Information Services Center, New York City. (Courtesy of Owen Steel Company, Inc.)
3 Table 5.1 may not be suitable for practical design conditions e.g. when a column is part of a continuous frame
o Sidesway? o Lateral deflection of building frame because of : Lateral loads, or Unsymmetrical vertical loads, or Unsymmetrical frame o Sidesway inhibited (braced frame), Fig. 7.1 (p. 214) Braced by diagonal bracing, or Braced by rigid shear wall o Sidesway uninhibited ( moment frame) o Alignment charts may help find k (the effective length factor) o Fig 7.2 introduces the alignment chart produced by Jackson and Moreland
To use the alignment charts o Preliminary sizes for girders and columns framing into the column in question is required o Assuming E = 29000 ksi for all columns and girders, the G is G = 10 for hinge support = 1 for fixed support
Figure 7.2 Jackson and Moreland alignment charts for effective lengths of columns in continuous frames.