geotech (version 1.0)

bearingCapacity: Ultimate Bearing Capacity

Description

This function computes the ultimate bearing capacity of a shallow foundation using the simple theory of Terzaghi (1943).

Usage

bearingCapacity(phi, c, B, L, D, Dw, gamma, gammaW = NA, metric, case = "general", shape = "square")

Arguments

phi

effective friction angle (deg)

c

effective cohesion (psf or kPa)

B

foundation width (ft or m), or foundation diameter for circular footings

L

foundation length (ft or m)

D

Depth of foundation (ft or m)

Dw

Depth of groundwater table below foundation base (ft or m)

gamma

unit weight of soil (pcf or kN/m^3)

gammaW

unit weight of water (default = 62.4 pcf for English units; 9.81 kN/m^3 for metric units)

case

"general" or "local" to indicate general or local shear failure ("general" is default)

shape

"square", "rectangle", "circle", "strip" (or "continuous")

metric

logical variable: TRUE (for metric units) or FALSE (for English units)

Value

kPa)

Details

• Either SI or English units can be used, but must stay consistent.
• When specifying the length and width, L should be the longer of the two lengths.
• When the groundwater table is deep or unknown, set Dw >= D.
• For local shear, the friction angle is reduced to a value equal to atan(2/3 * tan(phi)).
• For local shear, the cohesion is reduced to a value equal to 2/3*c.

References

Terzaghi, K. (1943). Theoretical Soil Mechanics, John Wiley, New York.

See Also

bearingPressure, bearingCapacityFactors

Examples

bearingCapacity(phi = 30, c = 10, B = 10, L = 10, D = 8, Dw = 6,
                gamma = 120, metric = FALSE, case = "local",
                shape = "square")