1. Beam Design

In beams generally,we start with deflection criteria, as the beam resist load in form of bending moment by deflection. So the first criteria is always deflection criteria.

For cantilever beams= 7

For Simply supported= 20

For continuous beams= 26

where the numerical values represents the (span/effective depth) ratio. Above values are valid only when span is less than or equal to 10m. From this criteria you will get a trial value of depth, from there assuming a proper grade of concrete and steel, you can calculate Moment of Resistance of the beam. But remember for comparing MOR, you should know either the overburden load along with dead load of structure or the gross moment acting on the beam.

As a trial value you will get an effective depth of 400mm, but i can bet you that will fail in the first trial only, you will need a effective depth of around 600–800mm for the span of 8m. Moreover it may be singly or doubly reinforced beam depending upon the total bending moment need to be resisted.

2.Column

It is a most complex component of a building, you need a lot of data, tables, curves and checks then only you can design a column, because it need to carry a large axial load, and the loading may be eccentric or may not, so for that we have to counter-check, axial bending and biaxial bending. You will also need SPD curves. I’ll generalise the procedure.

• Calculate the total axial load need to be transferred through one column.
• Adopt a section(rectangular, square, circular)
• Adopt a min size of 400mm
• As per the required length of column, check for type of member, i.e. Strut,Short column, or long column. Try adopting short column.
• Find effective length of the column, check for unsupported length of the column.
• Check slenderness ratio, it should be less than 12, for short column.
• Check for minimum eccentricity, for which column will be designed.
• Applying proper reduction factor as per the method adopted(WSM/LSM)
• Find out area of steel required.
• Adopt a suitable dia of tie bar as per codal provisions.
• Check for maximum spacing.
• If biaxial bending also exists, then either design for it or try to nullify the biaxial bending by increasing the size of column so that tension core broadens.