bearingCapacity: Ultimate Bearing Capacity

In geotech: Geotechnical Engineering

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)

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.

Value

Bearing capacity (q_ult) from Terzaghi's simple theory (psf or kPa)

Author(s)

James Kaklamanos <[e-mail]> and Kyle Elmy <[e-mail]>

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")

Example output

[1] 8286.072

geotech documentation built on May 1, 2019, 9:09 p.m.