Fig Redistribution procedures for frames

What Effective Span Beam

The effective span of a simply supported beam should normally be taken as the clear distance between the faces of supports plus one-third of the beam seating width at each end. However, where a bearing pad is provided between the slab and the support, the effective span should be taken as the distance between the centres of the bearing pads. The effective span of a beam continuous over its supports should normally be taken as the distance between the centres of the supports. The effective...

Sizes and reinforcement of columns

Slender Reinforced Concrete Column

Where possible it will generally be best to use 'stocky columns' i.e. generally for typical columns for which the ratio of the effective height to the least lateral dimension does not exceed 15 as this will avoid the necessity of designing for the effects of slenderness. Slenderness effects can normally be neglected in non-sway structures where the ratio of the effective height to the least lateral dimension of the column is less than 15. For the purpose of initial design, the effective height...

Division of moments between column and middle strips

The design moments obtained from analysis of the frames or from Table 5.4 should be divided between the column and middle strips in the proportions given in Table 5.5. Table 5.5 Distribution of design moments of flat slabs For the case where the width of column strip is taken as equal to that of the drop and the middle strip is thereby increased in width, the design moments to be resisted by the middle strip should be increased in proportion to its increased width. The design moments to be...

Initial design reinforced concrete

In the initial stages of the design of building structures it is necessary, often at short notice, to produce alternative schemes that can be assessed for architectural and functional suitability and which can be compared for cost. They will usually be based on vague and limited information on matters affecting the structure such as imposed loads and nature of finishes, and without dimensions, but it is nevertheless expected that viable schemes be produced on which reliable cost estimates can...