1985 Ed.]
Building (Construction) Regulations
[CAP. 123
B 65
103. (1) Both ends of each length of a column, other than a column of solid round section with shouldered ends, shall be properly prepared and dead square over the whole area of the ends.
(2) Column joints shall be close butted and the caps, base-plates and joint seating plates shall be in effective contact over the whole of the column end.
(3) This regulation shall not apply where sufficient gussets and rivets are provided to transmit the entire load.
104. (1) The foot of every column, other than a column of solid round section, shall have affixed thereto either a base-plate or a slab or bloom base.
(2) Slab or bloom bases shall be properly machined over the bearing surfaces and shall be in effective contact over the whole area of the machined end of the column.
(3) Columns of solid round section shall be provided with caps and bases, the bearing surfaces of which shall be properly machined. Those caps and bases shall be not less than 1.5 (d+75) mm in length or diameter, where d is the diameter of the column, or, where the column has a reduced end. If those columns have shouldered ends, the shoulders shall also be properly machined and the caps and bases shall be properly machined after being shrunk or screwed on.
(4) A bearing surface which is to be grouted directly to a foundation need not be machined if that bearing surface is true and parallel to the machined upper face.
(5) Caps, bases, base-plates and slab or bloom bases shall be of sufficient thickness to transmit and distribute load without exceeding the maximum stresses specified in regulation 97.
(6) (a) When the slab alone will distribute the load uniformly,
the minimum thickness of a rectangular slab shall be:
[Subsidiary]
Ends of columns.
Bases for columns.
L.N. 294/76.
3w
(42 p
B2
where t is the slab thickness in mm;
w is the pressure or loading on the underside of the base in MPa;
p is the permissible flexural stress in extreme fibres of slab bases in MPa;
A is the greater projection of the plate beyond the column in mm; and
B is the lesser projection of the plate beyond the column in mm.
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