Gross allowable bearing capacity

[georam]

Can anyone explain about a term "gross allowable bearing capacity" of soil for building foundations. How does it differ from allowable bearing capacity , or net bearing capacity ?
I assume that the term "allowable" means that a factor of safety is inherently included in the value (instead of ultimate bearing capacity), but what is the significant of the word "gross" ?

Thanks

 

[jeanesse]

Hi georam

Gross allowable bearing capacity means bearing capacity due all of the loads from surface to base of the foundation. This terms consider S.F., but settlements and new structure effect are not consider.

Net bearing capacity means the values of aditional loads due new building in the foundation base including any movement of the earth. This term not include S.F. and it not consider settlements effects.

Allowable bearing capacity means net allowable bearing capacity (it include S.F.). This term consider amount of bearing capacity, sort of estimate settlement and capacity of the building to resist it (building allowable settlement).