Design of Shallow Foundation (Isolated Footings)

Design a square footing for a column size of 400x400. The compression axial load for the load combination of (1.5 DL + 1.5 LL) is 2000 KN. The safe soil bearing capacity is 150 KN/m2 at a depth of 2 metres below E.G.L. Participants are free to go for either a tapered or stepped footing. Besides the total axial load, also account for the self-weight of the footing and soil above it. Assume M25 concrete grade. Do the following checks:

• If the gross bearing pressure under the footing is within safe bearing capacity
• Provide sufficient depth and longitudinal steel for resisting bending and shear
• Sufficient anchorage for column steel into the footing
• If the bearing pressure at column-footing joint is within 0.45 times the maximum concrete compressive strength

Provide a simple sketch showing the size of the footing, maximum and minimum depth of the section, flexural reinforcement in both directions and anchorage of column steel.

Please do go through the solved examples in the document provided with the challenge.

ANSWER:-

Aim:- To design the square footing using the given details.

Introduction:-

• Footings which are provided under each column independently are called as Isolated footings.
• They are usually square, rectangular or circular in section.
• Footing is laid on PCC. Before laying PCC, termite control liquid is sprayed on top face of PCC to restrict the termites to damage the footing.
• Isolated footings are provided where the soil bearing capacity is generally high and it comprises of a thick slab which may be flat or stepped or sloped.
• This type of footings are most economical when compared with the other kind of footings.

Steps involved in Design of Footing:-

• Determine the size of footing
• Upward pressure
• Depth of footing on the basis of B.M
• Area of reinforcement
• Check for one way shear
• Check for two-way shear

Procedure:-

RESULT:-

Using the given details the square footing has been designed successfully.