# Bearing capacity online calculator

## Problem: General:
Theory:
Shape:
Units:
Footing dimensions: Width: m
Length: m
Depth of embedment: m
Bending moment: kN-m
Soil properties: γ: kN/m3     γsat: kN/m3     γw: kN/m3
Depth of ground water table: m
Friction angle:
Cohesion intercept: kPa

## Solution:

Read Meyerhof's bearing capacity theory and formulas here.

Factor of Safety against bearing capacity (FS) =

Ultimate stress at bearing level (qb) = kPa = { Nc term: } + { Nq term: } + { Nγ term: }
Ultimate Load at bearing level (Qb) = kN

Eccentricity = eB = m
Effective width = B' = B - 2eB = m
Inclination from vertical axis = θ = °
Surcharge stress = q0 = kPa

Bearing Capacity Factors (N factors): [See formulas]
Nc =
Nq =
Nγ =

Shape factors: [See formulas]
Sc =
Sq =
Sγ =

Depth factors: [See formulas]
dc =
dq =
dγ =

Inclination factors: [See formulas]
ic =
iq =
iγ =

Hints and Tips on Bearing Capacity of Shallow Foundations:
- If there is no water table in the problem use a very large value for "depth of ground water". For instance 9999
- If you are solving a "Strip footing" it is better to use plane-strain friction angle rather than triaxial friction angle
- Meyerhof method does not have "Circular footing" in it, this online calculator uses an equivalent (in terms of area) square footing instead
- If you have layered soil (heterogeneous soil) of the same type (either granular or cohesive) you can use weighted average parameters; for instance if you have n layers of sands with γi and φi, use γ=sum(γi*Hi)/sum(Hi) and φ=sum(φi*Hi)/sum(Hi) where i=1, 2, ..., n
- For rectangular footing if the ratio of L/B>10 you can consider it as strip footing
- Effect of Ground Water Table on bearing capacity of shallow foundations

In geotechnical engineering, bearing capacity is the capacity of soil to support the loads applied to the ground. The bearing capacity of soil is the maximum average contact pressure between the foundation and the soil which should not produce shear failure in the soil. Ultimate bearing capacity (qf) is the theoretical maximum pressure which can be supported without failure; allowable bearing capacity (qa) is the ultimate bearing capacity divided by a factor of safety. Sometimes, on soft soil sites, large settlements may occur under loaded foundations without actual shear failure occurring; in such cases, the allowable bearing capacity is based on the maximum allowable settlement. There are three modes of failure that limit bearing capacity: general shear failure, local shear failure, and punching shear failure. Read more here...