Bearing capacity of Shallow Foundations - Part 02

Previously we talked about Trazaghi and Meyerhof bearing capacity equations. now will see about other equations,

Hansen's bearing capacity equation

This equation use to find the q ult in,
1) Inclined loaded,
2) Ground surface not horizontal,
3) footing is not horizontal cases

where,
C = soil cohesion

gamma b = unit weight of the soil below the foundation

B = footing width (least dimension)

q = overburden vertical stress (q=Df*gamma soil)

Nc, Nq, N gamma = bearing capacity factors (depends on phi)

Sc, Sq, S gamma = shape factors
dc, dq, d gamma = depth factors
ic, iq, i gamma = load inclination factors
gc, gq, g gamma = ground slope factors
bc, bq, b gamma = tilted base factors

and also,
Af = contact area of footing ( B x L)

Ca = adhesion between footing and soil
If footing is insitu cast Ca = C (same as soil cohesion )

Phi a is friction angle
If footing is insitu cast  Phi a = phi (same as soil parameter )

If there is no ground slope g factors are equal to 01

If there is no inclination of footings b factors are equal to 01

Vesic's bearing capacity equation

 
The equation and applications are same as hansen's bearing capacity equation, the difference is factors are difference. and also there is new addition, parallel forces to the footing.

where,
C = soil cohesion

gamma b = unit weight of the soil below the foundation

B = footing width (least dimension)

q = overburden vertical stress (q=Df*gamma soil)

Nc, Nq, N gamma = bearing capacity factors (depends on phi)

Sc, Sq, S gamma = shape factors
dc, dq, d gamma = depth factors
ic, iq, i gamma = load inclination factors
gc, gq, g gamma = ground slope factors
bc, bq, b gamma = tilted base factors