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)

Design and· detailing-illustrative examples 437
(a} Support B
s~~KS
3T32+2T25
(b) Span AB
3T25 U-bars
so~j
sol ill£,~~
lc l Support A
s~~Kf
3T25
Cdl Span BC
Fig.ll.S-9
ss:oNIIJ ::o
2T25 U-bars
(e) Support C
From Table 4.7-2,
Note that:
z
d = 0.94
X
d = 0.13
(a) As stated at the end of Section 4.5, BS 8110 does not allow zld to
be taken as greater than 0.95 in any case.
(b) xld = 0.13. Therefore 0.9x = (0.9)(0.13)(500) =59 mm < hr, i.e.
stress block within flange thickness.
From eqn (4.8-3),
_ M _ (522)(10 6 )
As - 0.87/yz - (0.87)(460)(0.94)(500)
= 2775 mm 2 Bottom 3T32 + 2T25 (3394 mm 2 )
End support A (Fig. 11.5-9(c)). Assume nominal fixing moment equal
to 40% of the initial fixed end moment-see Comments on Step 5 at the
end:
M = 40% of 507 kNm (Fig. 11.5-5: Case 1)
= 203 kNm
From Table 4.7-1 (or eqn 4.7-5),
K' = 0.156