K Kouzouki Engineering calculators
Concrete Foundations

Concrete footing design

Reinforced-concrete footings to IBC Chapter 18 and ACI 318-19 (adopted by IBC Ch. 19). Footings are sized for soil bearing at service loads and designed for one-way shear, two-way (punching) shear and flexure at factored loads — every equation, substitution, variable definition and code reference shown in full.

Spread Footing

Isolated column footing — soil bearing, one/two-way shear, flexure (ACI 318).

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Continuous Footing

Wall / strip footing — soil bearing, one-way shear, flexure (ACI 318).

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Combined Footing

Two-column footing — pressure, beam V/M envelope, punching & flexure (ACI 318).

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Retaining Wall

Cantilever wall — active/passive pressure, overturning, sliding, bearing & RC design (IBC 1807).

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Design basis. Allowable soil bearing is a geotechnical input — confirm with the project soils report. Concrete strength design (LRFD) uses the 1.2D + 1.6L combination; soil bearing uses service (ASD) loads. Each footing page carries an independent validation report.