Structural design of isolated footings

What the tool calculates

• Bending calculation using the reference section at 0.15·a (CEB-70)
• Rigidity criterion and punching shear check
• Minimum reinforcement by concrete class
• Cover based on environmental exposure, with a minimum of 7 cm for concrete cast directly against the ground

What you enter

• Footing and column geometry
• Design load and bending moment
• Concrete fck and environmental exposure class

What you receive

• Bending reinforcement
• Rigidity classification (rigid or flexible) and punching shear check where applicable
• Minimum concrete cover

References and limits of applicability

• ABNT NBR 6118:2023 — Design of concrete structures (bending, punching shear, minimum reinforcement, cover)

Checks and considerations

• Flexible footing that fails the punching shear check
• Cover below 7 cm for concrete cast directly against the ground

How it works

The structural analysis uses geometry and design actions to check bending and rigidity, with punching shear checks where applicable. Minimum reinforcement depends on concrete class, while cover depends on exposure and construction conditions. The adopted allowable bearing pressure must come from a compatible geotechnical assessment.

Example of use

Using preliminary dimensions from the geotechnical study, enter the column geometry and actions on the footing. Compare alternative depths and review rigidity classification, punching shear where applicable, and reinforcement required in both directions.

Generated documents

These documents are assembled within your project using data from the corresponding tools.

• Foundation calculation report — Combine the project's SPT logs, bearing capacity calculations and structural designs for piles, pile caps, footings and belled caissons in one PDF. The document consolidates selected items; technical checks remain within each tool.
• Structural calculation report — Combine the project's saved structural results in one PDF, with the selected calculations and their references, including NBR 6118:2023 for concrete members. Check the standards applicable to each member before issuing the document; consolidation does not replace design review.
• Concrete, formwork and reinforcement quantities — Determine concrete volumes, formwork areas and steel masses from the structural designs of piles, pile caps, footings and belled caissons, with recalculation of the members and reference to NBR 7480 for mass per unit length. Review quantities, allowances for waste and assumptions; export to PDF, Word, Excel/XML (.xls), XML or DXF. Pricing is not included.