1985 Ed.]
Building (Construction) Regulations
CAP. 123
Bill
[Subsidiary]
Psc and Pst are the permissible stresses in the reinforcement for compression and tension, respectively; and
X =
585 × 690 + 1.8Py
375Py × 103
690 +
Es
where cold worked reinforcement is used, the denominator in the formula for X should be increased to:
At the load P, the corresponding eccentricity of load eh relative to the centre of the section is given by the following equation:
Pheb +
ds — d2
2
= Pechá12 X(1 -
Pret
Y) + A × Psc (d, d2)
where d2 is the depth to the compressive reinforcement.
(2) When the section is controlled by compression, the permissible load (P) on the column is related to the permissible load (Po) for an axially loaded column, as given in regulation 143(1)(a), and the eccentricity (e) of the load (P) relative to the centre of the section, according to the following equation:
P +
L.N. 294/76.
L.N. 95/78.
1 +
Po
eh
(3) When the applied load is less than Ph the section is controlled by tension and the permissible load is given by the following equation:
P =
Pstbd (0.5 -
h/d { (0.5 - - a{
Y)
ď
e
+/(0.5 -
d
Pse d Y)2 + 7
Pec
d2
d
-) + Y(2
Y)
L.N. 95/78.
d
d
where - Y =
2
+√(0.5
[[]
Pst - Pse
Pec
d
total area of reinforcement
bd
; and
h is the overall depth of the column section.
1