B 82
[Subsidiary]
Bending moments.
Beams and slabs
spanning in 1 direction.
CAP. 123 Building Construction, Regulations
[1985 Ed.
(ii) where the slab is assumed to be spanning independently in the same direction as the beam, such transverse reinforcement shall be near the top surface of the slab: and
(b) the quantity of such reinforcement shall
(i) be related to the shear stress in the slab produced by its acting as the compression member of the T-beam or L-beam: and
(ii) in no case be less than 0.3 per cent of the gross cross-sectional area of the slab.
135. (1) Bending moments in beams and slabs shall be calculated for the effective span and all loading thereon.
(2) The bending moments to be provided for at a cross-section of a continuous beam or slab shall be the maximum positive and negative moments at such cross-section, allowing in both cases, if so desired, for the reduced moments due to the width of the supports, for the following arrangements of super-imposed loadings--
(a) alternate spans loaded and all other spans unloaded;
(b) any 2 adjacent spans loaded and all other spans unloaded.
(3) Except where the approximate values for bending moments assumed in regulation 136(1)(c) are used, the negative moments at the supports for any assumed arrangements of loading may each be increased or decreased by not more than 15 per cent, in which case the calculated simultaneous positive moments in the 2 adjacent spans shall be decreased or increased, respectively, by the same numerical value and the positive moments elsewhere in the span adjusted accordingly.
136. (1) The bending moments in beams and slabs spanning in 1 direction shall be calculated on 1 of the following assumptions--
(a) beams shall be designed as members of a continuous framework, with monolithic connexion between the beams and columns, and the bending moments calculated taking into account the resistance of the columns to bending:
(b) beams and slabs shall be designed as continuous over supports and capable of free rotation about them. Nevertheless, where the supports to beams or slabs are monolithic with them and stiff in relation to them, the beams or slabs shall be designed with due regard to such stiffness: or
(c) unless more exact estimates are made, the bending moments in uniformly loaded beams and slabs continuous over 3 or more approximately equal spans shall be assumed to have the values given in Table XXXIII.