F. K. Kong MA, MSc, PhD, CEng, FICE, FIStructE, R. H. Evans CBE, DSc, D ès Sc, DTech, PhD, CEng, FICE, FIMechE, FIStructE (auth.)-Reinforced and Prestressed Concrete-Springer US (1987)

448 Practical design and detailing
539 •270
2
435
693 =347
2
406 = 203 521 = 261
2 2
19m) 17m) 19m) 17m)
435 435
Ia) Floor junction
I b) Roof junction
Fig. 11.5-14
M in column = 365 x 14Ji 7 = 107 kNm
Roof junction (Fig. 11.5-14(b))
L (f) = (435 + 203 + 261) x 1<P = 899 x 10 3 mm 3
Out-of-balance moment = 226 kNm
435
M at top of 3rd floor column = 226 x 899
Step 4 Effective column height
Foundation to 1st floor
From eqn (7.2-2),
effective column height le = {Jl0
From Table 7.2-1,
North-South direction:
Hence
fJ = 0.9 (end conditions: top = 1, bottom = 3)
lex = 0.9lo
= (0.9)(4000) = 3600 mm
lex/ h = 3600/380
= 9.5 < 15
East-West direction:
fJ = 1.0 (end condition: top = 3, bottom = 3)
Hence
ley = (1.0)(4000) = 4000 mm
(see Comments at end)
= 109 kNm