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Footing Bearing Pressure (Eccentric Load)

Elastic bearing pressure under axial load plus biaxial moment: σ = N/A ± M/W. Kern check determines whether the footing has full contact with the soil.

Inputs

Axial load N kN

Moment about long axis M_L kN·m

Moment about short axis M_B kN·m

Footing short dimension B m

Footing long dimension L m

Allowable bearing pressure (optional) kPa

Results

Eccentricity e_L—

Kern limit L/6—

Within kern (full contact)?—

σ_max—

σ_min—

Uplift risk?—

Within allowable?—

Citations

Mechanicsσ = N/A ± M/W (elastic bearing pressure, full-contact assumption). Universal engineering mechanics, not code-specific.

KernNo uplift requires eccentricity within the kern: e ≤ L/6 (and B/6). Beyond the kern, a partial-contact (triangular) pressure analysis is required — this tool flags but does not compute that case.

VERIFYEngine: engine/rc-tr.js footingPressure(). Tested in tests/rc-tr.test.js against 3 independent hand-calculated cases (eccentric-within-kern, eccentric-with-uplift, concentric-uniform).

Engine: rc-tr.js · General mechanics (code-independent) ·

Preliminary calculation tool. This checks contact/uplift only — it does not check soil bearing capacity (see the geotechnical bearing-capacity tool) or structural punching shear.