Question

What are the steps for designing footings for a building? (In terms of dimensions, reinforcing steel, ...)

according to aci code (metric system)

Answer 1

I would expalin the basic steps required to design the footing. Without going into the calculations and exact expression these step will help you to understand the basic sequence that need to be followed for footings.

The Basic Steps of designing isolated footing are mentioned below.

1) Find the Base area requrired for unfacatored load combinations based on Soil bearing Capacity.

Area Required > Load/soil bearing capacity

2) Assume the depth such that the effective depth for bottom reinforcement is atleast 6inches(150mm) for first trail.

3) Calculate the bending moment & shear force at critical sections i.e at face of column for Bending moment & at distance d (effective depth of footing) for factored load combinations.

4) Design the flexural reinforcement for the moment obtained.

5) check the shear strength of fotting for provided reinforcement. If less than designed then increase the depth and repeat the process from step 2.

6) Check the footing for punching, If failed increase the depth of footing & repeat from step 2.

7) Detail the footing.