How to create the design of a square column footing

In this construction video tutorial, you will learn the step-by-step process for creating the design of a square column footing.

Details about column footing:

Column Footing is also known as independent footing. An independent footing is set up under a column or either related member for transferring the concentrated load in the form of uniformly loads on the soil underneath.

The footing appears as square, rectangular or circular in plan. Based on the load to be borne and the bearing strength of the soil, it is made of brick masonry, stone, R.C.C., steel grill-age etc. Due to low bending strength, the footings are built up with brick, stone or plain concrete with adequate depth to bear heavy loads securely.

The depth of plain concrete footing is considerably decreased by arranging reinforcements at its base to undertake tensile stresses. R.C.C. column footings come in the shape of circular, rectangular or square in plan. The footing is reinforced both-ways with mild steel ribbed bars which are provided at proper angles to one another at equivalent distances apart.

Suppose, there is a column with dimension 400 x 500 and you have to determine the proper size of the footing. There are different types of checks like one way shear, two way shear, checks for cracking, checks for development length as well as the loads to be transferred to the soil underneath and the load bearing strength of the soil to combat that loads.

The design is made on the basis of the following data :-

Design an isolated square footing for square column having dimension 400 mm x 400 mm for axial load of 800 KN (load enforced to column). Apply M-20 grade concrete, Fe-250 grade steel. Safe bearing strength of soil is 120 KN/m2.

The following steps are involved in the design process :-

Size of footing, Net upward pressure (P), Bending moment (Mu), Depth of footing, Reinforcement – Verify the scope for cracking, Inspection of one way shear, Inspection of two way shear, Inspection of development length, Load transmitted from column to footing

The design for any column is based on the IS codes S:16 and IS : 456-2000.

To learn the complete process for designing a square column footing, go through the following video tutorial.

Video Source: Civiconcepts